JP4246034B2 - Transmission terminal, communication terminal, radio communication system, and radio communication method - Google Patents

Description

  The present invention relates to a packet-switching transmission terminal, a communication terminal, a wireless communication system, and a wireless communication method that transmit and receive data via wireless communication.

  In recent years, in the field of wireless communication systems, products based on communication standards using a 2.4 GHz frequency band have become widespread. This frequency band is called an ISM (Industrial Scientific Medical) band, and can have a communication function without license for industrial, scientific, medical, and other uses. Products that meet these standards have been developed.

  Wireless communication systems employing Bluetooth systems include communication devices such as mobile phones and PHS (Personal Handy Phone), data processing devices such as personal computers, personal digital assistants (PDAs), digital cameras, and portable audio devices. Wireless communication devices are wirelessly connected to realize data communication in a short-distance network of about 100 m at the maximum.

  Bluetooth provides each terminal with a role such as a master or a slave when performing communication. A master is a terminal corresponding to a server in a server / client system of a computer network, and manages and controls a wireless network in Bluetooth. On the other hand, a slave is a terminal corresponding to a client in a server / client system of a computer network, and its communication is managed and controlled by the master.

  In Bluetooth, a single master and a plurality of slaves constitute a wireless network and perform communication. In Bluetooth, the master configures a limited network topology called a piconet. One piconet always includes one master and one or more slaves, and synchronization information necessary for connection such as time and frequency is managed by the master.

  In the configuration example of the piconet, as shown in FIG. 9 which is an explanatory diagram of the present invention, up to seven slaves can be actively connected simultaneously per piconet. FIG. 9 shows a state in which the master 10 is connected to seven slaves 11 to 17 and performs communication between the master and the slave.

  Bluetooth communicates with other terminals using spread spectrum frequency hopping. In general, frequency hopping by the spread spectrum method is performed by selecting random hopping (switching of carrier frequency) over the entire band composed of a plurality of narrow frequency bands. Is set so that the frequency band of the communication signal is spread and spread.

  Specifically, a band of 79 MHz is secured by performing random hopping 1600 times per second with a frequency width of 1 MHz, that is, every 625 us. In addition, even if there are devices that generate interfering frequencies due to hopping, the influence can be reduced as much as possible.

  Furthermore, a time division duplex (TDD) system is employed in order to ensure that the master and slaves perform order transmission and reception reliably. Time division slot multiplexing determines the timing of data transmission / reception between a master and a slave.

  Specifically, the master determines the transmission / reception timing based on time information managed by the master itself, the master transmission slot (slave reception slot) that is the transmission timing from the master to the slave, and the transmission timing from the slave to the master The slave transmission slot (master reception slot) is clearly separated.

  The timing of the master transmission slot and the slave transmission slot is managed by the master. The master transmission slot and the slave transmission slot are alternately present on the time axis and never overlap each other. The master designates a slave to be transmitted in the master transmission slot and transmits data.

  On the other hand, the slave receives transmission data from the master using the transmission slot timing of the master as the reception slot timing of the slave under management by the master. Similarly, transmission from the slave to the master is performed in a slave transmission slot (master reception slot).

  In order to realize frequency hopping and time division slot multiplexing, Bluetooth transmits data by dividing it into packets. A packet is a set of data flowing through the network, and includes a destination address, a transmission source address, a flag indicating the contents of the data, an error detection code, and the like. The packet structure in Bluetooth is shown in FIG. The packet is composed of an access code consisting of 68 bits or 72 bits, a packet header consisting of 54 bits, and a payload for storing actual data. The payload has a variable length and a maximum of 2745 bits.

  As shown in FIG. 11, the access code is composed of a 4-bit preamble, a 64-bit sync word, and a 4-bit trailer. The preamble and trailer repeat the pattern of 1 and 0 according to the MSB and LSB of the sync word. The trailer is omitted when there is no subsequent data such as a packet header or payload.

  As shown in FIG. 12, the packet header includes 3-bit AM_ADDR, 4-bit TYPE, 1-bit FLOW, 1-bit ARQN, 1-bit SEQN, and 8-bit HEC. AM_ADDR is assigned by a master to a slave in order to identify a slave that is communicating in a piconet. TYPE is a field indicating what kind of data the packet is. In Bluetooth V1.1, NULL, POLL, FHS, DM1, DM3, DM5, DH1, DH3, DH5, HV1, HV2, HV3, DV , 14 types of AUX1 are defined.

  FLOW is a field for managing the flow control of packets transmitted and received on the communication link. When the reception buffer for temporarily storing reception data is filled, STOP (FLOW = 0) is set to notify the partner terminal that data reception is impossible. Further, when there is a space in the reception buffer, GO (FLOW = 1) is set to notify the counterpart terminal that data reception is possible.

  ARQN is used to notify the transmitting terminal whether or not there is an error in the received packet. When it is determined that there is no error in the received packet, ACK (ARQN = 1) is used to notify that there is no error. If it is determined that there is an error in the received packet, NAK (ARQN = 0) is used to notify that there is an error.

  SEQN determines whether it is a retransmitted packet by alternately repeating 1 and 0 each time a new packet is transmitted. If the SEQN of the previously received packet is the same as the SEQN of the currently received packet, it is determined that the same packet has been retransmitted.

  HEC is an error detection code for a total of 10 bits of AM_ADDR, TYPE, FLOW, ARQN, and SEQN described above. ARQN and SEQN are exchanged between a plurality of terminals that perform transmission and reception, and are information for confirming data consistency with each other, and thus can be defined as retransmission control information.

  The packet header becomes 54-bit information by 1/3 rate error correction coding (1/3 FEC) of 18-bit data consisting of these 6 fields.

  As shown in FIG. 13, the payload is composed of three parts: a payload header composed of 8 bits or 16 bits, a variable length payload body, and an error detection code (CRC) composed of 16 bits. The error detection code (CRC) is used to detect whether or not there is an error in the payload header and payload body.

  A conventional terminal adopting Bluetooth is shown in FIG.

First, the wireless terminal includes a wireless communication unit 100, a CPU 111 , a ROM 112, and a RAM 113. The wireless communication unit 100, the CPU 111, the ROM 112, and the RAM 113 are connected to each other via a bus 110. The wireless communication unit 110 includes a control unit 101, a transmission unit 102, a reception unit 103, a switch SW 104, an antenna 105, and an interface unit 106.

  The control unit 101 controls the overall operation of the wireless communication unit 100, and supplies control signals to the transmission unit 102, the reception unit 103, the interface unit 106, and the like according to instructions from the CPU 111, In response to the output signal, response processing for the functional block is performed. It also sets the frequency and timing for transmission and reception.

  The transmission unit 102 performs data shaping, packet assembly, and the like to transmit data, and passes the data to the antenna 105 via the switch SW104.

  The receiving unit 103 receives data received by the antenna 105 via the switch SW 104 and shapes the data into a format suitable for packet decomposition and processing by the wireless communication unit 100.

  The switch SW 104 switches between transmission and reception modes according to instructions from the control unit 101. In the transmission mode, the transmission unit 102 and the antenna 105 are connected via the switch SW104, and the reception unit 103 and the antenna 105 are disconnected to enable data transmission. On the other hand, in the reception mode, the reception unit 103 and the antenna 105 are connected via the switch SW104, and the transmission unit 102 and the antenna 105 are turned off to enable data reception. The interface unit 106 exchanges data with the host device 120.

  FIG. 15 shows a procedure in which terminals adopting Bluetooth transmit / receive packets to / from each other by the master / slave method. Here, a description will be given using a state where one master performs packet transmission / reception with two slaves 1 and 2.

  As described above, Bluetooth uses time division slot multiplexing, and the transmission slot and the reception slot are clearly separated. In FIG. 15, the transmission slot is represented as TX and the reception slot is represented as RX in time series.

  At time t1, the master transmits the packet a to the slave 1 together with information of ARQN = 1 and SEQN = 0. The slave 1 that has normally received the packet a transmits the packet b to the master together with the information of ARQN = 1 and SEQN = 0 at time t2 as a response to the packet a.

  Next, at time t3, the master transmits the packet c to the slave 2 together with information on ARQN = 1 and SEQN = 0. The packet a at the time t1 and the SEQN value of the packet c at the time t3 are the same, but there is no problem because the SEQN value is managed for each transmission destination.

  The slave 2 that has received the packet c transmits the packet d to the master together with information of ARQN = 1 and SEQN = 0 at time t4 as a response to the packet c.

  Next, since the master normally receives the packet b from the slave 1 at time t2, the master transmits the packet e to the slave 1 at time t5 together with information of ARQN = 1 and SEQN = 1. The slave 1 that has received the packet e transmits the packet f to the master together with the information of ARQN = 1 and SEQN = 1 at time t6 as a response to the packet e.

  Next, since the master normally receives the packet d from the slave 2 at time t4, the master transmits the packet g to the slave 2 together with information of ARQN = 1 and SEQN = 1 at time t7. . The slave 2 that has received the packet g transmits the packet h together with the information of ARQN = 1 and SEQN = 1 to the master at time t8 as a response to the packet g.

  In Bluetooth, the master and the slave clarify the transmission slot and the reception slot as described above, and exchange the retransmission control information such as ARQN and SEQN together with the data, thereby mutually confirming the transmission / reception state. Here, it is described that the master alternately transmits packets to the slave 1 and the slave 2, but the transmission order is not necessarily this because the master can arbitrarily determine the transmission order.

  Next, handling of errors in transmission and reception will be described with reference to FIG. Originally, both the master and the slave transmit a packet having both retransmission control information of ARQN and SEQN. However, for the sake of simplicity of explanation, the master ARQN and the result that does not affect the results within the scope of the explanation. The description of the slave SEQN is omitted and only one slave is provided. Further, even when not explicitly described in the following description, transmission and reception of each information of SEQN and ARQN is assumed to be performed in a packet format having such information.

First, at time t1, the master transmits the packet a together with the information of SEQN = 0 toward the slave. The slave that has received the packet a returns ARQN = 1 to the master at time t2. At time t3, the master transmits the packet b to the slave together with the information of SEQN = 1. Here, when the slave fails in this reception, ARQN = 0 is returned to the master at time t4. The master that has received ARQN = 0 from the slave determines that the slave has not received packet b normally, and retransmits packet b at time t5. When receiving the packet b normally, the slave returns ARQN = 1 to the master at time t6. However, here, when the master fails to receive the information of ARQN = 1, it is determined that the mutual transmission / reception is not completed, and the packet b is retransmitted at time t7. Since retransmission is performed at this time, SEQN is the same as SEQN = 1 as in the previous time. The slave that has received the packet b returns information of ARQN = 1 at time t8. The master that has received the information of ARQN = 1 transmits the packet c together with the information of SEQN = 0 to the slave at time t9. The slave that has received this returns information of ARQN = 1 to the master at time t10. Thus, even if a reception error occurs, a packet that could not be received can be retransmitted.
JP 2001-45012 A (published February 16, 2001)

  As described above, when there is no error in transmission / reception of ARQN and SEQN exchanged between the master and the slave, no problem occurs in transmission / reception of the packet.

  However, in an environment where the reception level of radio waves is low, or noise or radio waves of other wireless systems are mixed, there is a high possibility that a radio error will occur.

  As shown in FIG. 16, when a control packet is transmitted and received between the master and the slave, for example, when the master transmits to the slave with SEQN = 1 at time t7, the slave recognizes that SEQN = 0. The master determines that it has received the packet c, which is the next packet, instead of retransmitting the packet b, even though it has transmitted the packet b, and recognizes that the packet b has not been received. Omission error occurs.

  Further, for example, when the control packet (ARQN = 1) indicating ACK does not reach the master as at time t6 shown in FIG. 16, the packet b is transmitted to the slave even though the packet b is correctly transmitted. Must be transmitted again from the master to the slave at time t7, resulting in a decrease in overall throughput due to misrecognition of the response.

  In addition, when the receiving terminal erroneously recognizes ARQN and SEQN, it is conceivable that a packet that is originally an error is recognized as normal data, or a packet that is originally normal is recognized as an error. For example, when the slave transmits SEQN = 0 but the slave recognizes SEQN = 1, it is the same as the SEQN of the packet received by the slave immediately before that, so it is recognized as an error and ARQN = 0 is set. It will be sent back to the master. Similarly, when the master transmits SEQN = 1 but the slave recognizes SEQN = 0, it is the same as the SEQN of the packet received immediately before by the slave, so it is recognized as an error and ARQN = Return 0 to the master.

  When the slave misidentifies the SEQN of the packet transmitted by the master, the slave responds to the master with ARQN = 0. If the master misrecognizes this as ARQN = 1, the master determines that packet transmission / reception is normally performed, and as a result, packet loss occurs. This phenomenon will be described in detail with reference to FIG.

  First, the master transmits packet a to the slave with SEQN = 0 at time t1. The slave receives this normally, and returns ARQN = 1 to the master at time t2. The master receives this, and transmits packet b to the slave with SEQN = 1 at time t3.

  Here, it is assumed that an error has occurred and the slave has erroneously recognized that SEQN = 0. Since it is determined that the slave has not received normally, the slave returns ARQN = 0 to the master at time t4. Here, it is assumed that the master misrecognizes the return from the slave as ARQN = 1.

  In this case, since the master recognizes that the reply to the packet b transmitted at time t3 is normal, the packet b is not correctly transmitted to the slave in practice, Proceed to the process. At time t5, the master transmits packet C to the slave with SEQN = 0. Since the slave receives it as SEQN = 0, it determines that the packet received at time t3 is the same as SEQN, and requests the master to retransmit packet c at time t5. At this time, the state is fixed to SEQN = 0 and ARQN = 0, resulting in confusion in transmission / reception.

  In order to solve the above problem, a technique disclosed in Patent Document 1 has been proposed, but since a different payload header format such as SR (Selective Repeat) -ARQ is used, it is compatible with existing Bluetooth. There is a problem that sex cannot be maintained. In addition, it is necessary to cope with a new format, which causes problems such as an increase in circuit scale, complicated structure, complicated control, and complicated data structure.

  Furthermore, in the technique of Patent Document 1, a technique is proposed in which a modulo identifier is defined and used as transmission / reception control information. However, retransmission requests associated with reception errors are limited only within a range where the modulo identifier is the same. Therefore, there arises a problem that data having different modulo identifiers cannot be handled.

  The present invention has been made in view of the above-described conventional problems, and its purpose is to avoid undetection of erroneous reception and packet drop error, and to ensure continuity of packet transmission / reception, thereby improving throughput and communication quality. It is to provide a transmission terminal, a communication terminal, a wireless communication system, and a wireless communication method that can improve the performance.

In order to solve the above problems, the transmitting terminal of the present invention includes interface means for connecting to a host device, and in the transmitting terminal that transmits data to the receiving terminal in units of packets using wireless communication, the data consistency A transmission means for transmitting a packet having retransmission control information, which is information for confirming the transmission, a number assignment means for assigning a serial number to the packet to be transmitted, and a transmission means and a number assignment means. and a transmission control means for controlling the operation, the number applying means, the serial number, is characterized in that applied to the payload body of the packet. Note that the host device is a personal computer or a PDA (Personal Digital Assistant), and serves to control various functions (devices) that are built in or connected externally.

  Further, in the transmitting terminal according to the present invention, in the transmitting terminal described above, when there is no request for retransmission from the receiving terminal that has received the packet, the transmission control unit sets the serial number value assigned to the previously transmitted packet. The method is characterized in that a certain number of packets are added to the next packet and transmitted.

  Further, in the transmitting terminal according to the present invention, in the transmitting terminal described above, when there is no request for retransmission from the receiving terminal that has received the packet, the transmission control unit sets the value of the serial number assigned to the previously transmitted packet, It is characterized in that the packet is transmitted by giving it to the next packet after being reduced by a certain number.

  Further, in the transmitting terminal according to the present invention, in the transmitting terminal described above, when the receiving terminal that has received the packet requests retransmission, the transmission control means sets the value of the serial number assigned to the previously transmitted packet. It is characterized in that the same packet is transmitted without change.

Further, in the transmitting terminal according to the present invention, in the transmitting terminal described above, the number assigning unit is necessary for storing a maximum value determining unit that determines a maximum value of the serial number and a maximum value of the determined serial number. It is characterized by comprising data length information giving means for giving the data length information to the payload body .

In order to solve the above-described problem, the communication terminal of the present invention is a communication terminal that transmits and receives data in units of packets using radio, a receiving unit that receives a packet transmitted from the transmitting terminal described above, and a reception unit from payload body of the packet, and the serial number obtaining means for obtaining granted serial number, is characterized by having a communication control means for controlling the operation of said receiving means and the serial number obtaining means.

Further, the communication terminal according to the present invention is the communication terminal described above, wherein the communication control means is a retransmission control which is information for confirming the consistency of the data stored in the packet header of the received packet. information is content to request retransmission to the transmission source, if the serial number assigned to the received packet is not the value that follows the serial number assigned to a packet previously received one to the transmission source It is characterized by requesting retransmission of the previous packet.

Further, the communication terminal according to the present invention is the communication terminal described above, wherein the communication control means is a retransmission control which is information for confirming the consistency of the data stored in the packet header of the received packet. When the information is a content requesting retransmission to the transmission source, the transmission source is requested to retransmit the packet.

The communication terminal according to the present invention is characterized in that in the communication terminal described above, the communication terminal includes data length information acquisition means for acquiring the data length information given in the payload body of the received packet.

  Moreover, in order to solve the above-mentioned problems, the wireless communication system of the present invention includes the above-described transmission terminal and the above-described communication terminal.

In order to solve the above-described problem, the wireless communication method of the present invention is characterized in that transmission is performed by assigning a serial number in the payload body of a packet using the transmission terminal described above.

In order to solve the above-described problem, the wireless communication method of the present invention is characterized by performing transmission / reception by assigning a serial number in the payload body of a packet using the communication terminal described above.

  Further, the wireless communication method of the present invention is characterized in that, in order to solve the above-described problem, the serial number assigned to the transmission packet of the transmission terminal is compared with the serial number assigned to the reply packet from the reception terminal. Yes.

  The wireless communication method of the present invention is the wireless communication method described above, wherein the serial number assigned to the reply packet from the receiving terminal is different from the serial number assigned to the transmission packet transmitted immediately before by the transmitting terminal. The transmitting terminal is characterized by determining that there is an abnormality in reception at the receiving terminal.

  The wireless communication method of the present invention is the wireless communication method described above, wherein when the transmitting terminal determines that there is an abnormality in reception, it retransmits a packet having the same content regardless of a retransmission request from the receiving terminal. It is characterized by doing.

  Further, the wireless communication method of the present invention is the wireless communication method described above, wherein the transmitting terminal has the same serial number given to the packet returned from the receiving terminal as the serial number given to the packet transmitted immediately before. The same packet as the packet transmitted immediately before is retransmitted.

Further, the wireless communication method of the present invention is the above-described wireless communication method, wherein the transmitting terminal has a serial number assigned to the packet returned from the receiving terminal different from the serial number assigned to the packet transmitted immediately before, and When the retransmission control information, which is information for confirming the consistency of the data written in the packet header of the received packet , has a value requesting retransmission to the transmitting terminal, the previous packet is retransmitted. It is characterized by doing.

Further, the wireless communication method of the present invention is the above-described wireless communication method, wherein the transmitting terminal has a serial number assigned to the packet returned from the receiving terminal different from the serial number assigned to the packet transmitted immediately before, and When the retransmission control information, which is information for confirming the consistency of the data written in the packet header of the received packet , has a value that does not require retransmission to the transmitting terminal, the next packet is retransmitted. It is characterized by.

  The wireless communication method of the present invention is characterized in that, in the wireless communication method described above, the transmission terminal requests the reception terminal to perform packet transmission / reception using a serial number.

  The wireless communication method of the present invention is the wireless communication method described above, wherein when the receiving terminal is requested to perform packet transmission / reception using the serial number from the transmission terminal, packet transmission / reception using the serial number is performed. It is characterized by returning a response as to whether or not to perform.

  Further, the wireless communication method of the present invention is the wireless communication method described above, wherein the transmitting terminal confirms a response as to whether or not to perform packet transmission / reception using the serial number from the receiving terminal. When the packet transmission / reception using the wireless communication is rejected, the communication is performed by the packet transmission / reception system that does not use the serial number used in Bluetooth.

  Further, the wireless communication method of the present invention is the wireless communication method described above, wherein when the transmitting terminal confirms that the packet transmission / reception using the serial number is performed with the receiving terminal, the serial number is assigned. The receiving terminal is requested to perform packet transmission / reception using a packet provided with a serial number field as a part of the payload body at the head.

  The wireless communication method of the present invention is the above wireless communication method, wherein the receiving terminal transmits and receives a packet by a packet having a serial number field as a part of the payload body as a serial number assigning method from the transmitting terminal. When it is requested to perform, the response is whether to approve or not.

  In addition, in the wireless communication method of the present invention, in the wireless communication method described above, it is recognized that the transmission terminal performs packet transmission / reception by a packet having a serial number field attached to the head as a part of the payload body by the reception terminal. In this case, packet transmission / reception by the packet is selected.

  Further, the wireless communication method of the present invention is the wireless communication method described above, wherein when the transmitting terminal confirms that the packet transmission / reception using the serial number is performed with the receiving terminal, the serial number is assigned. The receiving terminal is requested to perform packet transmission / reception using a packet attached to the head of the data length area designation field and the serial number field as part of the payload body.

  The wireless communication method of the present invention is the wireless communication method described above, wherein the receiving terminal uses a data length area designation field and a serial number field as a method of assigning a serial number from the transmitting terminal, and a part of the payload body. When it is requested to perform packet transmission / reception with a packet attached to the head as follows, a reply is made as to whether or not to approve packet transmission / reception with the packet.

  Further, the wireless communication method of the present invention is the above-described wireless communication method, wherein the transmitting terminal uses a packet in which the receiving terminal assigns a data length area designation field and a serial number field to the head as part of the payload body. When packet transmission / reception is permitted, packet transmission / reception by the packet is selected.

  Further, the wireless communication method of the present invention is the above-described wireless communication method, wherein the transmitting terminal performs packet transmission / reception by a packet provided with a serial number field as a part of the payload body from the receiving terminal. A packet transmission / reception method that does not use the serial number used in Bluetooth when it is also refused to perform packet transmission / reception with the packet assigned to the head of the area designation field and serial number field as part of the payload body. It is characterized by performing communication.

  In an environment where the reception level of radio waves is low, noise or radio waves from other wireless systems are mixed, wireless errors occur, and overall throughput decreases due to misrecognition of responses and packet loss occurs. Is more likely to do.

  However, in the transmission terminal of the present invention, the number assigning means assigns a serial number to the packet to be transmitted, and the transmission control means controls the operation of the transmitting means and the number assigning means so as to perform communication using the serial number in the packet. To do.

  Therefore, continuity of packet transmission can be ensured by giving a serial number to a packet to be transmitted. Therefore, it is possible to detect a packet loss error and improve communication quality. Further, by avoiding erroneous reception due to an error on the radio such as packet loss, it is possible to improve the throughput of communication by increasing the possibility of transmitting / receiving normal data.

  In the present invention, for example, by storing a serial number in the payload body, it is possible to comply with the existing Bluetooth specification. In addition, the new format does not complicate the data structure, and does not increase the circuit scale, complicate the structure, or complicate the control.

  Therefore, it is possible to provide a transmission terminal capable of improving throughput and communication quality by avoiding erroneous reception and undetected packet missing errors and ensuring continuity of packet transmission / reception.

  Further, in the transmitting terminal of the present invention, when there is no request for retransmission from the receiving terminal that received the packet, the transmission control means increases the serial number value assigned to the previously transmitted packet by a certain number to increase the next packet. To send a packet.

  Therefore, since the serial number is increased by a certain number in order, packet loss can be prevented.

  In the transmitting terminal of the present invention, when there is no retransmission request from the receiving terminal that received the packet, the transmission control means reduces the serial number value assigned to the previously transmitted packet by a certain number to the next packet. Give it and send the packet.

  That is, in order to prevent packet loss, it is not always possible to increase the serial number by a certain number in order, but it is also possible to decrease the serial number value by a certain number in order.

  In the transmission terminal of the present invention, the transmission control means transmits the same packet without changing the value of the serial number assigned to the previously transmitted packet when there is a retransmission request from the receiving terminal that has received the packet. Let

  Therefore, since the value of the serial number is not changed at the time of retransmission, the consistency between the packet contents and the serial number can be ensured, and packet loss can be reliably prevented.

  In the transmission terminal of the present invention, the number assigning means assigns the maximum value determining means for determining the maximum value of the serial number and data length information necessary for storing the determined maximum value of the serial number to the packet. Data length information adding means is provided.

  That is, when the maximum value determining means is not used, the bit width of the serial number is fixed. In this case, there is no effect in communication with data with a large packet size, but in communication with a small packet size, if the bit width of the serial number is increased, the ratio of storing the data body decreases and the data transmission efficiency Becomes worse.

  In the present invention, in order to avoid this problem, the bit width of the serial number can be changed depending on the size of the packet.

  Further, in the communication terminal of the present invention, the receiving means for receiving the packet transmitted from the transmitting terminal, the serial number acquiring means for acquiring the serial number assigned from the received packet, the receiving means and the serial number acquiring means Communication control means for controlling the operation.

  Therefore, since communication using a serial number can be performed, a communication terminal capable of improving throughput and communication quality by avoiding erroneous reception and undetected packet missing errors and ensuring continuity of packet transmission / reception. There is an effect that can be provided.

  In the communication terminal according to the present invention, the communication control means stores the retransmission control information asking whether or not retransmission is required, which is stored in the received packet. If the assigned serial number is not a value following the serial number assigned to the previously received packet, the transmission source is requested to retransmit the previous packet.

  Therefore, the retransmission control information and the serial number can be used to reliably avoid undetected packet loss errors and perform retransmission to prevent packet loss.

  In the communication terminal according to the present invention, the communication control means retransmits the packet to the transmission source when the retransmission control information stored in the received packet is a content requesting the transmission source to retransmit. Request.

  Therefore, the retransmission control information and the serial number can be used to reliably avoid undetected packet loss errors and perform retransmission to prevent packet loss.

  The communication terminal of the present invention further includes data length information acquisition means for acquiring data length information given to the received packet.

  Therefore, the data length information acquisition unit can acquire the data length information given to the received packet.

  The wireless communication system of the present invention includes the above-described transmission terminal and the above-described communication terminal.

  In the wireless communication system of the present invention, transmission is performed by assigning a serial number to a packet using the transmission terminal described above.

  Further, in the wireless communication system of the present invention, transmission / reception is performed by assigning a serial number to a packet using the communication terminal described above.

  Therefore, it is possible to provide a wireless communication system capable of improving throughput and communication quality by avoiding erroneous reception and undetected packet missing errors and ensuring continuity of packet transmission / reception.

  In the wireless communication method of the present invention, the serial number assigned to the transmission packet of the transmitting terminal is compared with the serial number assigned to the reply packet from the receiving terminal.

  Therefore, there is an effect that it is possible to provide a wireless communication method that can improve throughput and communication quality by avoiding erroneous reception and undetected packet missing errors and ensuring continuity of packet transmission / reception.

  Further, in the wireless communication method of the present invention, when the serial number assigned to the reply packet from the receiving terminal is different from the serial number assigned to the transmission packet transmitted immediately before by the transmitting terminal, the transmitting terminal Judge that there was an abnormality in reception.

  Therefore, when serial numbers do not come in order, there is an effect that it can be determined that there is an abnormality.

  Further, in the wireless communication method of the present invention, when the transmitting terminal determines that there is an abnormality in reception, the transmitting terminal retransmits a packet having the same content regardless of the retransmission request from the receiving terminal.

  Therefore, when the serial numbers do not come in order, it is judged that there is an abnormality and the packet is prevented from being lost by retransmitting the packet.

  In the wireless communication method of the present invention, the transmitting terminal is the same as the packet transmitted immediately before when the serial number assigned to the packet returned from the receiving terminal is the same as the serial number assigned to the packet transmitted immediately before. Resend the packet.

  Therefore, it is possible to reliably retransmit a packet having a transmission error, and to prevent packet loss.

  In the wireless communication method of the present invention, the transmitting terminal has a serial number assigned to the packet returned from the receiving terminal different from the serial number assigned to the packet transmitted immediately before and is written in the received packet. When the retransmission control information has a value for requesting retransmission to the transmitting terminal, the previous packet is retransmitted.

  In the wireless communication method of the present invention, the transmitting terminal has a serial number assigned to the packet returned from the receiving terminal different from the serial number assigned to the packet transmitted immediately before and is written in the received packet. When the retransmission control information has a value that does not request retransmission to the transmitting terminal, the next packet is retransmitted.

  Therefore, in consideration of the retransmission control information, it is possible to retransmit a packet having a transmission error more reliably, and to prevent packet loss.

  In the wireless communication method of the present invention, the transmitting terminal requests the receiving terminal to perform packet transmission / reception using the serial number.

  Therefore, there is an effect that it is possible to ask for consent rather than forcing the receiving side to send and receive packets using the serial number.

  In the wireless communication method of the present invention, when the receiving terminal is requested to perform packet transmission / reception using the serial number from the transmission terminal, the receiving terminal returns a response as to whether to perform packet transmission / reception using the serial number. return.

  Therefore, the receiving terminal is also provided with an opportunity to return a reply as to whether or not to perform packet transmission / reception using the serial number.

  In the wireless communication method of the present invention, the transmission terminal performs packet transmission / reception using the serial number from the reception terminal as a result of confirming whether or not to perform packet transmission / reception using the serial number from the reception terminal. If it is rejected, communication is performed using a packet transmission / reception method that does not use the serial number used in Bluetooth.

  Therefore, when the reception side refuses to perform packet transmission / reception, there is an effect of performing communication in a packet transmission / reception system that does not use the serial number used in Bluetooth.

  Further, in the wireless communication method of the present invention, when the transmitting terminal confirms that packet transmission / reception using the serial number is performed with the receiving terminal, the serial number field is set to the payload body as a serial number assigning method. It requests the receiving terminal to perform packet transmission / reception using a packet attached to the head as a part.

  Therefore, as a method for assigning the serial number, there is an effect that packet transmission / reception can be performed by a packet provided with the serial number field at the head as a part of the payload body.

  Further, in the wireless communication method of the present invention, when the receiving terminal is requested to perform packet transmission / reception by a packet having a serial number field attached to the head as a part of the payload body as a serial number assigning method from the transmitting terminal. In response to whether or not to approve.

  Therefore, whether or not the receiving terminal approves when the sending terminal is requested to perform packet transmission / reception using a packet with the serial number field added at the head as part of the payload body as a method of assigning the serial number. It has the effect of being given the opportunity to reply.

  Further, in the wireless communication method of the present invention, when the transmitting terminal is permitted to perform packet transmission / reception by a packet having a serial number field added to the head as a part of the payload body by the receiving terminal, the packet transmission / reception by the packet is performed. Select.

  Therefore, there is an effect that the transmission terminal selects packet transmission / reception by the packet based on the consent of the reception terminal.

  Further, in the wireless communication method of the present invention, when the transmitting terminal confirms that packet transmission / reception using the serial number is performed with the receiving terminal, as a method for assigning the serial number, a data length region designation field, The receiving terminal is requested to perform packet transmission / reception using a packet attached to the head of the serial number field as a part of the payload body.

  Therefore, the transmitting terminal requests the receiving terminal to perform packet transmission / reception using a packet with a data length area designation field and a serial number field as a part of the payload body as a serial number assignment method. There is an effect that can be.

  In the wireless communication method of the present invention, as a method for assigning a serial number from the transmitting terminal, the receiving terminal uses a packet with a packet having a data length area designation field and a serial number field as a part of the payload body. When it is requested to perform transmission / reception, there is an effect that an opportunity to reply whether or not to approve packet transmission / reception by the packet is given.

  Further, in the wireless communication method of the present invention, the transmitting terminal is permitted to perform packet transmission / reception by a packet having a data length area designation field and a serial number field as a part of the payload body by the receiving terminal. If the packet is received, packet transmission / reception by the packet is selected.

  Therefore, there is an effect that the transmission terminal selects packet transmission / reception by the packet based on the consent of the reception terminal.

  Further, in the wireless communication method of the present invention, the transmitting terminal can perform packet transmission / reception by a packet having a serial number field attached to the head as a part of the payload body from the receiving terminal. When packet transmission / reception using a packet attached to the head as a part of the payload body is also rejected, communication is performed using a packet transmission / reception method that does not use the serial number used in Bluetooth.

  Therefore, if two types of methods are rejected as a method of assigning a serial number from the transmitting terminal, the transmitting terminal performs communication using a packet transmission / reception method that does not use the serial number used in the conventional Bluetooth. There is an effect that can be performed.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 13 as follows.

  As shown in FIG. 4, the wireless terminal 1 as a transmission terminal, a reception terminal, and a communication terminal according to the present embodiment includes a wireless communication unit 20, a CPU 31, a ROM 32, and a RAM 33. The wireless communication unit 20, the CPU 31, the ROM 32, and the RAM 33 are connected to each other via the bus 30. The wireless communication unit 20 includes a control unit 21 as a transmission control unit, a reception control unit, and a communication control unit, a transmission / reception setting unit 22 as a number assigning unit, a data length information acquisition unit, and a serial number acquisition unit, and a transmission unit. A transmission unit 23, a reception unit 24 as a reception unit, a switch SW25, an antenna 26, and an interface unit 27 as an interface unit are provided.

  The control unit 21 controls the overall operation of the wireless communication unit 20, and supplies control signals to the transmission / reception setting unit 22, the transmission unit 23, the reception unit 24, the switch SW 25, and the like according to instructions from the CPU 31. In response to an output signal from the functional block, response processing for the functional block, setting of frequency and timing for transmission and reception, and the like are performed.

  The present embodiment is characterized in that it includes a transmission / reception setting unit 22 as compared with FIG. 14 showing the prior art.

  The transmission / reception setting unit 22 performs processing related to a serial number field, which will be described later, as necessary, and instructs the transmission unit 23 and the reception unit 24. The transmission unit 23 performs data shaping, packet assembly, and the like to transmit data, and passes the data to the antenna 26 via the switch SW25. The receiving unit 24 receives the data received by the antenna 26 via the switch SW25, and shapes the data into a format suitable for packet decomposition and processing by the wireless communication unit 20.

  The switch SW25 switches between transmission and reception according to an instruction from the control unit 21. That is, in the transmission mode, the transmission unit 23 and the antenna 26 are connected, and the reception unit 24 and the antenna 26 are turned off to enable data transmission. On the other hand, in the reception mode, the receiving unit 24 and the antenna 26 are connected, and the transmitting unit 23 and the antenna 26 are turned off to enable data reception.

  The interface unit 27 exchanges data with the host device 40 connected to the wireless communication unit 20. The host device 40 is a personal computer or a PDA (Personal Digital Assistant), and plays a role of controlling various functions (devices) built in or externally connected. Further, the wireless terminal 1 determines its operation under the control of the host device 40.

  Here, the wireless terminal 1 according to the present embodiment can also function as a master or a slave under the control of the control unit 21 in the wireless communication system. Therefore, the present invention is also applied to a communication system in which a device performing a master or slave function such as Bluetooth is not fixed.

  Next, the wireless communication method of this embodiment will be described.

  In the present embodiment, as in Bluetooth, each terminal is provided with a role such as a master or a slave when performing communication. A master is a terminal corresponding to a server in a server / client system of a computer network, and manages and controls a wireless network in Bluetooth. On the other hand, a slave is a terminal corresponding to a client in a server / client system of a computer network, and its communication is managed and controlled by the master.

  In this embodiment, one master and a plurality of slaves constitute a wireless network and perform communication. The master forms a limited network topology called a piconet. One piconet always includes one master and one or more slaves, and synchronization information necessary for connection such as time and frequency is managed by the master.

  In the configuration example of the piconet, as shown in FIG. 9, up to seven slaves can be actively connected simultaneously per piconet. FIG. 9 shows a state in which the master 10 is connected to seven slaves 11 to 17 and performs communication between the master and the slave.

  In this embodiment, communication is performed with other terminals using frequency hopping by a spread spectrum method. In general, frequency hopping by the spread spectrum method is performed by selecting random hopping (switching of carrier frequency) over the entire band composed of a plurality of narrow frequency bands. Is set so that the frequency band of the communication signal is spread and spread.

  Specifically, a band of 79 MHz is secured by performing random hopping 1600 times per second with a frequency width of 1 MHz, that is, every 625 us. In addition, even if there are devices that generate interfering frequencies due to hopping, the influence can be reduced as much as possible.

  Furthermore, a time division duplex (TDD) system is employed in order to ensure that the master and slaves perform order transmission and reception reliably. Time division slot multiplexing determines the timing of data transmission / reception between a master and a slave.

  Specifically, the master determines the transmission / reception timing based on time information managed by the master itself, the master transmission slot (slave reception slot) that is the transmission timing from the master to the slave, and the transmission timing from the slave to the master The slave transmission slot (master reception slot) is clearly separated.

  The timing of the master transmission slot and the slave transmission slot is managed by the master. The master transmission slot and the slave transmission slot are alternately present on the time axis and never overlap each other. The master designates a slave to be transmitted in the master transmission slot and transmits data.

  On the other hand, the slave receives transmission data from the master using the transmission slot timing of the master as the reception slot timing of the slave under management by the master. Similarly, transmission from the slave to the master is performed in a slave transmission slot (master reception slot).

  In this embodiment, in order to realize frequency hopping and time division slot multiplexing, data is divided into packets and transmitted. A packet is a set of data flowing through the network, and includes a destination address, a transmission source address, a flag indicating the contents of the data, an error detection code, and the like.

  FIG. 10 shows a packet structure in the present embodiment. The packet is composed of an access code consisting of 68 bits or 72 bits, a packet header consisting of 54 bits, and a payload for storing actual data. The payload has a variable length and a maximum of 2745 bits.

  As shown in FIG. 11, the access code is composed of a 4-bit preamble, a 64-bit sync word, and a 4-bit trailer. The preamble and trailer repeat the pattern of 1 and 0 according to the MSB and LSB of the sync word. The trailer is omitted when there is no subsequent data such as a packet header or payload.

  As shown in FIG. 12, the packet header includes 3-bit AM_ADDR, 4-bit TYPE, 1-bit FLOW, 1-bit ARQN, 1-bit SEQN, and 8-bit HEC. AM_ADDR is assigned by a master to a slave in order to identify a slave that is communicating in a piconet. TYPE is a field indicating what kind of data the packet is. In Bluetooth V1.1, NULL, POLL, FHS, DM1, DM3, DM5, DH1, DH3, DH5, HV1, HV2, HV3, DV , 14 types of AUX1 are defined.

  FLOW is a field for managing the flow control of packets transmitted and received on the communication link. When the reception buffer for temporarily storing reception data is filled, STOP (FLOW = 0) is set to notify the partner terminal that data reception is impossible. Further, when there is a space in the reception buffer, GO (FLOW = 1) is set to notify the counterpart terminal that data reception is possible.

  ARQN is used to notify the transmitting terminal whether or not there is an error in the received packet. When it is determined that there is no error in the received packet, ACK (ARQN = 1) is used to notify that there is no error. If it is determined that there is an error in the received packet, NAK (ARQN = 0) is used to notify that there is an error.

  SEQN determines whether it is a retransmitted packet by alternately repeating 1 and 0 each time a new packet is transmitted. If the SEQN of the previously received packet is the same as the SEQN of the currently received packet, it is determined that the same packet has been retransmitted.

  HEC is an error detection code for a total of 10 bits of AM_ADDR, TYPE, FLOW, ARQN, and SEQN described above. ARQN and SEQN are exchanged between a plurality of terminals that perform transmission and reception, and are information for confirming data consistency with each other, and thus can be defined as retransmission control information.

  The packet header becomes 54-bit information by 1/3 rate error correction coding (1/3 FEC) of 18-bit data consisting of these 6 fields.

  As shown in FIG. 13, the payload is composed of three parts: a payload header composed of 8 bits or 16 bits, a variable length payload body, and an error detection code (CRC) composed of 16 bits. The error detection code (CRC) is used to detect whether or not there is an error in the payload header and payload body.

  On the other hand, the present embodiment is characterized in that transmission / reception is performed by assigning a serial number to a packet.

  A packet transmission / reception procedure performed by assigning a serial number to the packet and using processing with SEQN and ARQN together will be described with reference to FIG. However, only the packet transmission from the master to the slave is focused here. In other words, the packet transmission from the slave to the master is omitted, and only the response operation for the packet transmission from the master is described. Even when not specified in the following description, transmission and reception of each information of SEQN, ARQN and serial number is not performed. It is assumed that it is performed in a packet format having such information. The serial number is denoted as SN.

  As shown in FIG. 1, first, the master transmits packet a to the slave at time t1, and at this time, serial number SN = 0 is assigned to packet a. The packet a has information such as SEQN = 0.

  When receiving the packet a, the slave gives the serial number SN = 0 at time t2 and returns ARQN = 1 to the master. At this time, if the slave has data to be transmitted to the master, the data is transmitted together with the serial number SN and ARQN. If there is no data, only the serial number SN and ARQN are returned to the master, and the data in the packet is empty.

  By receiving ARQN = 1, the master determines that the slave has received the packet a having the serial number SN = 0, and transmits the packet b having the serial number SN = 1 to the slave at time t3. . That is, the packet b has information such as SEQN = 1 indicating that it is a new next packet.

  Here, consider a case where the slave receives the packet b but erroneously recognizes that SEQN = 0. Since the packet a and the SEQN received at the time t1 are the same, the slave determines that there is an abnormality in the reception. At the time t4, the slave assigns the serial number SN = 1 and returns ARQN = 0 to the master. Request resend.

  However, if the master misrecognizes this as ARQN = 1, the master misunderstands that the transmission at time t3 was successful, and transmits the packet c with the serial number SN = 2 to the slave at time t5. The packet c has information such as SEQN = 0 indicating that it is a new next packet. Although the slave receives the packet c, since the packet b and the SEQN received at the time t3 are the same, it is determined that an abnormality is recognized in the received packet, and at the time t6, the serial number SN = 2 is assigned to the master. Returns ARQN = 0 to request retransmission of the packet. In accordance with a request from the slave, the master transmits a packet c with the serial number SN = 2 to the slave at time t7.

  Although the slave receives the packet c, since the packet b and the SEQN received at the time t3 are the same, it is determined that the reception is abnormal, and at the time t8, the serial number SN = 3 is assigned and the master receives the ARQN. = 0 is returned, and retransmission of the packet is requested.

  The slave increments the serial number SN by 1 regardless of the data content as a response to the reception of data from the master. In other words, whether or not the reception has been successful can be made by a response by ARQN, and there is no function for determining whether or not to increase the serial number SN.

  Next, since the serial number SN = 2 assigned to the packet transmitted at time t7 is different from the serial number SN = 3 assigned to the packet received from the slave, the master sets the previous serial number SN = 1. It is determined that the transmission of the assigned packet b (transmitted at time t3) has not ended normally, and the packet b is retransmitted at time t9.

  When the slave receives packet b normally, serial number SN = 1 is assigned at time t10 and ARQN = 1 is transmitted to the master. By this procedure, transmission of the packet b from the master to the slave is successful, and transmission / reception after the packet c is resumed.

  In the above description, the serial number SN is described in ascending order starting from 0, but the start value does not have to be 0 and may change in descending order. Further, the alphabetic characters given to the packet are given for explanation and have no relation to the actual data contents.

  As described above, even if erroneous reception or erroneous recognition due to an error on the radio occurs, since the serial number SN is given to the packet, a packet drop error or the like that occurs due to dependence only on ARQN and SEQN It is possible to avoid the above-mentioned problems such as a decrease in overall throughput due to misrecognition of a response and confusion in transmission / reception due to erroneous recognition of retransmission control information, and to ensure continuity of packet transmission / reception.

  Next, the control procedure on the master side until the packet transmission abnormality is judged from the change of the serial number SN and the retransmission is performed will be described in detail with reference to the flowchart of FIG.

  First, when transmitting a packet, the serial number SNtx of the transmission packet is stored (S1). Next, when the packet is received, the serial number SNrx of the received packet is confirmed (S2). Thereafter, the serial number SNtx of the transmission packet is compared with the serial number SNrx of the reception packet (S3).

  If the comparison results are the same, the ARQN of the received packet is confirmed (S4). When ARQN = 1, it is determined that packet transmission / reception is normally performed, and the next packet is transmitted (S6). If ARQN = 0, it is determined that the previously transmitted packet has not been received normally, and the same packet is retransmitted (S7).

  On the other hand, if the comparison results in S3 are different, the ARQN of the received packet is confirmed (S5). When ARQN = 1, the same packet is retransmitted (S8). This means that the comparison result in S5 is the same, and the transmission / reception can be normally performed, and the serial numbers should match.

  Therefore, it is determined that the result of ARQN = 1 is wrong, and the packet transmitted earlier is retransmitted just in case. When ARQN = 0, the serial number and the ARQN are not normal, so it is determined that an abnormality has occurred in the previous packet transmission instead of the currently transmitted packet, and retransmission is performed from the previous packet ( S9). With this series of control procedures, as described above, continuity of packet transmission / reception can be ensured. Note that S6 and S7 can be realized by a conventional technique that does not use a serial number, and S8 and S9 can be realized for the first time by this embodiment.

  Next, means for assigning the serial number SN to the transmission packet will be described below.

  As a method for realizing this, there is a method of inserting data indicating a serial number at the head of the payload body. This method can be implemented without significantly changing the existing system in that the data content included in the packet is improved without changing the format of the packet. With respect to this method, two patterns will be described with reference to FIGS.

  First, as the simplest method, as shown in FIG. 3A, a method of preparing a serial number field at the head as a part of the payload body is conceivable. In this example, 8 bits are prepared as the serial number field. In this case, 256 serial numbers SN from 0 to 255 can be assigned.

  By assigning serial number SN = 0 to the first packet and assigning serial numbers SN changed in ascending order to subsequent packets, serial numbers SN from 0 to 255 can be assigned in order. When the serial number SN reaches the maximum value, it returns to the minimum value again.

  By repeating this operation, it becomes possible to repeat infinitely with a limited data length. Conversely, a method may be adopted in which the serial number SN = 255 is assigned to the first packet, and the serial number SN changed in descending order is assigned to the subsequent packets. Here, although the serial number field is described as 8 bits, it is not limited to 8 bits. The serial number SN assigned to the first packet may be an arbitrary value.

  On the other hand, as shown in FIG. 3B, there is a method in which a data length area designation field and a serial number field are prepared at the head as part of the payload body.

  The data length area designation field stores a value indicating the bit length of the subsequent serial number field. The data length area designation field uses, for example, the top 4 bits of the payload body that can exist in the range of 0 to 2745 bits as the data length area designation bit. In this case, since 16 values of 0 to 15 can be realized, the serial number SN that can be expressed by 16 bits can be handled. Although the data length area designation bit is described as 4 bits here, it is not limited to 4 bits.

  Here, as described above, the two methods for providing the serial number SN are provided for the following reason.

  In other words, if the bit width of the serial number field is fixed, the packet use efficiency decreases when the bit width used as the data area is small. In a wireless communication system using a packet system including Bluetooth, since the length generally differs depending on the type of packet, it is not preferable to fix the length uniquely for the above reason. In order to avoid this problem, it is necessary to change the sizes of the serial number field and the data length designation area field in consideration of the packet length.

  Here, the method of determining the maximum value of the serial number field can be determined by setting a value in a register (control data storage area) prepared internally using software, for example. When the master side device that controls communication performs this setting, the setting can be made for all devices in the piconet in the communication state.

  As described above, although two methods have been described in the present embodiment, a configuration may be adopted in which both methods can be implemented and selected.

  Also, the serial number SN shown in FIGS. 3 (a) and 3 (b) is applied to the transmission / reception setting unit 22 as a maximum value determining means for determining the maximum value of the serial number SN, and the determined maximum value of the serial number SN. This is performed by the transmission / reception setting unit 22 as data length information adding means for adding data length information necessary for storage to the packet.

  The above method can be applied regardless of the type of packet, the positioning of a terminal such as a master / slave, and the physical and logical positioning of the terminal. As a result, as a method using a modulo identifier, a retransmission request accompanying a reception error is limited only within a range in which the modulo identifiers as proposed in the cited document 1 are the same, and for data having different modulo identifiers. Therefore, it is possible to avoid erroneous reception of all packets and realize reliable packet transmission / reception without causing a problem that cannot be dealt with.

  Next, the processing procedure of this embodiment will be described with reference to FIG. At the start of connection, a confirmation operation is performed between the master and the slave as to whether the serial number method is applied. In the following explanation, the master confirms / requests whether the serial number system is applied to the slave, but this is not necessarily the case, and the slave applies the serial number system to the master. It is also possible to confirm and request.

  First, in step S1, the master confirms whether to use the serial number method for the slave. When not using, it progresses to step S6, the conventional means, ie, the system which does not use a serial number system, is applied, and transmission / reception is started.

  On the other hand, when the serial number method is used, it is confirmed in step S2 whether or not the first means (serial number information storage means shown in FIG. 3A) is used. When using, it progresses to step S4, performs the connection which applied the 1st means, and starts transmission / reception. If not used, it is checked in step S3 whether or not the second means (serial number information storage means shown in FIG. 3B) is used. When using, it progresses to step S5 and the transmission / reception which applied the 2nd means is started. If not used, it means that neither the first means nor the second means is used, and the process proceeds to step S6 to apply the conventional means and start transmission / reception.

  As described above, in FIG. 5, the communication method is determined after the confirmation of steps S1 to S3 at most three times.

  Here, FIG. 6 and FIG. 7 show processing procedures when only the first means is provided and when only the second means is provided. Since the concept is the same as the above processing procedure, the description is omitted here.

  Finally, the communication control procedure using this embodiment will be described with reference to FIG.

  As shown in FIG. 8, the master sends a connection request S41 to the slave. The slave that has received the connection request S41 from the master returns a connection response S42 indicating whether or not to connect to the master to the master. When the master that has received the connection response S42 from the slave signifying the agreement requests the use of the serial number method, the master sends a serial number method use request S43 to the slave. The slave that has received the serial number method use request S43 from the master returns a serial number method use response S44 indicating whether or not to approve the serial number method use to the master. If no agreement is obtained regarding the use of the serial number system, the subsequent steps are omitted and the data transmission / reception S50 is started by the conventional system.

  On the other hand, when an agreement is obtained regarding the use of the serial number method in the serial number method use response S44, the master transmits a first means use request S45 to the slave. The slave that has received the first means use request S45 from the master returns a first means use response S46 that indicates whether to use the first means to the master.

  When an agreement is obtained regarding the use of the first means, data transmission / reception S50 is started by the first means. On the other hand, when an agreement is not obtained regarding the use of the first means, the master transmits a second means use request S47 to the slave. The slave that has received the second means use request S47 from the master returns a second means use response S48 indicating whether or not to use the second means to the master. If an agreement is obtained regarding the use of the second means, data transmission / reception S50 is started by the second means.

  On the other hand, if no agreement is obtained regarding the use of the second means, the data transmission / reception S50 is started by the conventional method.

  Here, it is described that the master sends all processing requests from the connection request S41 to the second means use request S47, and the slave responds. However, the slave sends individual processing requests to the master. May respond.

  Since the serial number SN can be assigned to the transmission packet by using the configuration and processing procedure of the present embodiment described above, it is possible to avoid the above problem and ensure the continuity of packet transmission. Become.

  Further, since the serial number SN to be assigned is stored in the payload body, it is possible to comply with the existing Bluetooth specification. Further, in the reception that cannot be prevented only by the determination based on the retransmission control information such as ARQN and SEQN without causing problems such as an increase in circuit scale, complicated structure, complicated control, and complicated data structure. Packet loss and reception errors can be avoided.

  Further, it is possible to improve the throughput of communication by avoiding erroneous reception due to a packet drop or an error on the radio of ARQN and SEQN bits and increasing the possibility of transmitting / receiving normal data.

  Furthermore, it is possible to detect a packet drop error that cannot be detected only with the ARQN and SEQN bits, and to improve communication quality.

  As described above, conventionally, in a transmission terminal, a communication terminal, a wireless communication system, and a wireless communication method, in an environment where the reception level of radio waves is low, or noise and radio waves of other wireless systems are mixed, There is a problem that an error occurs on the radio, and there is a high possibility that an overall response is lowered due to a misrecognition of a response and a packet drop occurs.

  However, in the wireless terminal 1 according to the present embodiment, the transmission / reception setting unit 22 assigns a serial number SN to a packet to be transmitted, and the control unit 21 performs transmission using the transmission unit 23 and the serial number SN to perform communication using the packet. The operation of the transmission / reception setting unit 22 is controlled.

  Therefore, the continuity of packet transmission can be ensured by giving the serial number SN to the packet to be transmitted. Therefore, it is possible to detect a packet loss error and improve communication quality. Further, by avoiding erroneous reception due to an error on the radio such as packet loss, it is possible to improve the throughput of communication by increasing the possibility of transmitting / receiving normal data.

  In the present embodiment, for example, by storing the serial number SN in the payload body, it is possible to comply with the existing Bluetooth specification. In addition, the new format does not complicate the data structure, and does not increase the circuit scale, complicate the structure, or complicate the control.

  Accordingly, it is possible to provide the wireless terminal 1 that can improve throughput and communication quality by avoiding erroneous reception and undetected packet loss errors and ensuring continuity of packet transmission / reception.

  Further, in the wireless terminal 1 of the present embodiment, when there is no retransmission request from the counterpart wireless terminal 1 that has received the packet, the transmitting unit 23 sets the value of the serial number SN assigned to the previously transmitted packet. Then, the packet is transmitted by adding a certain number to the next packet.

  Therefore, since the serial number SN increases in order by a certain number, packet loss can be prevented.

  In the wireless terminal 1 of the present embodiment, when there is no retransmission request from the counterpart wireless terminal 1 that has received the packet, the control unit 21 sets the value of the serial number SN assigned to the previously transmitted packet, It is possible to reduce the number and add to the next packet to transmit the packet.

  That is, in order to prevent packet loss, it is not always necessary to increase the serial number SN in order by a fixed number, but it is also possible to decrease the value of the serial number SN in order by a fixed number.

  Further, in the wireless terminal 1 of the present embodiment, when there is a retransmission request from the counterpart wireless terminal 1 that has received the packet, the control unit 21 sets the value of the serial number SN assigned to the previously transmitted packet. Send the same packet unchanged.

  Therefore, since the value of the serial number SN is not changed at the time of retransmission, the consistency between the packet contents and the serial number SN can be ensured, and packet loss can be reliably prevented.

  Further, in the wireless terminal 1 of the present embodiment, the transmission / reception setting unit 22 is necessary for storing the function as the maximum value determining means for determining the maximum value of the serial number SN and the maximum value of the determined serial number SN. A function as data length information attaching means for assigning data length information to the packet is provided.

  That is, when the maximum value determining means shown in FIG. 3B is not used, as shown in FIG. 3A, the bit width of the serial number SN is fixed. In this case, there is no effect in communication with data with a large packet size. However, in communication with a small packet size, if the bit width of the serial number SN is increased, the ratio of storing the data body decreases and data transmission is performed. Inefficiency.

  In this embodiment, in order to avoid this problem, the bit width of the serial number SN can be changed depending on the size of the packet.

  Further, in the wireless terminal 1 of the present embodiment, a receiving unit 24 that receives a packet transmitted from the transmitting-side wireless terminal 1, a transmission / reception setting unit 22 that acquires a serial number SN given from the received packet, And a control unit 21 that controls operations of the reception unit 24 and the transmission / reception setting unit 22.

  Therefore, since communication using the serial number SN can be performed, wireless communication that can improve throughput and communication quality by avoiding undetected erroneous reception and missing packet errors and ensuring continuity of packet transmission / reception. Terminal 1 can be provided.

  Further, in wireless terminal 1 of the present embodiment, control unit 21 requests retransmission from the source of SEQN and ARQN, which are retransmission control information for asking whether retransmission is necessary, stored in the received packet. If the serial number SN assigned to the received packet is not a value following the serial number SN assigned to the previously received packet, the sender is requested to retransmit the previous packet.

  Therefore, using the SEQN and ARQN and the serial number SN, it is possible to reliably avoid undetected packet loss errors and perform retransmission to prevent packet loss.

  Further, in the wireless terminal 1 of the present embodiment, the control unit 21 transmits a packet to the transmission source when the SEQN and ARQN stored in the received packet are contents for requesting retransmission to the transmission source. Request retransmission of.

  Therefore, by using the SEQN and ARQN and the serial number SN, it is possible to reliably avoid undetected packet loss errors and perform retransmission to prevent packet loss.

  In addition, the wireless terminal 1 according to the present embodiment includes a transmission / reception setting unit 22 that acquires data length information given to a received packet.

  Therefore, the transmission / reception setting unit 22 can acquire the data length information given to the received packet.

  In addition, the wireless communication system of the present embodiment includes a wireless terminal 1 as a master and a wireless terminal 1 as a slave.

  Further, in the wireless communication system of the present embodiment, transmission is performed by assigning a serial number SN to a packet using the wireless terminal 1 as a master.

  Further, in the wireless communication system according to the present embodiment, transmission / reception is performed by assigning a serial number SN to a packet using the wireless terminal 1 as a master.

  Therefore, it is possible to provide a wireless communication system capable of improving throughput and communication quality by avoiding erroneous reception and undetected packet loss errors and ensuring continuity of packet transmission / reception.

  In the wireless communication method of the present embodiment, the serial number SN assigned to the transmission packet of the wireless terminal 1 is compared with the serial number SN assigned to the reply packet from the wireless terminal 1 as the receiving terminal.

  Therefore, it is possible to provide a wireless communication method that can improve throughput and communication quality by avoiding erroneous reception and undetected packet missing errors and ensuring continuity of packet transmission / reception.

  Further, in the wireless communication method of the present embodiment, the serial number SN given to the reply packet from the wireless terminal 1 as the receiving terminal is the serial number given to the transmission packet sent immediately before by the wireless terminal 1 as the sending terminal. When it is different from the number SN, the wireless terminal 1 as the transmitting terminal determines that there is an abnormality in reception at the wireless terminal 1 as the receiving terminal.

  Therefore, when the serial numbers SN do not come in order, it can be determined that there is an abnormality.

  Further, in the wireless communication method according to the present embodiment, when the wireless terminal 1 as the transmitting terminal determines that there is an abnormality in reception, the same contents regardless of the retransmission request from the wireless terminal 1 as the receiving terminal Resend the packet.

  Therefore, when the serial numbers SN do not come in order, it is determined that there is an abnormality, and the packet dropout can be prevented by retransmitting the packet.

  Further, in the wireless communication method of the present embodiment, the wireless terminal 1 as the transmitting terminal receives the serial number SN assigned to the packet returned from the wireless terminal 1 as the receiving terminal, and attached to the packet transmitted immediately before. When it is the same as the number SN, the same packet as the packet transmitted immediately before is retransmitted.

  Therefore, it is possible to reliably retransmit a packet in which a transmission error has occurred and to prevent packet loss.

  Further, in the wireless communication method of the present embodiment, the wireless terminal 1 as the transmitting terminal receives the serial number SN assigned to the packet returned from the wireless terminal 1 as the receiving terminal, and attached to the packet transmitted immediately before. When the SEQN and ARQN written in the received packet are different from the number SN and have a value for requesting retransmission to the wireless terminal 1 as the transmitting terminal, the previous packet is retransmitted.

  Further, in the wireless communication method of the present embodiment, the wireless terminal 1 as the transmitting terminal receives the serial number SN assigned to the packet returned from the wireless terminal 1 as the receiving terminal, and attached to the packet transmitted immediately before. When the SEQN and ARQN written in the received packet are different from the number SN and have a value that does not require retransmission to the wireless terminal 1 as the transmitting terminal, the next packet is retransmitted.

  Therefore, in consideration of SEQN and ARQN, a packet with a transmission error can be retransmitted more reliably and packet loss can be prevented.

  In the wireless communication method of the present embodiment, the wireless terminal 1 as a transmitting terminal requests the wireless terminal 1 as a receiving terminal to perform packet transmission / reception using the serial number SN.

  Therefore, instead of forcing the receiving side to send and receive packets using the serial number SN, it is possible to ask for consent.

  In the wireless communication method of the present embodiment, when the wireless terminal 1 as the receiving terminal is requested to perform packet transmission / reception using the serial number SN from the wireless terminal 1 as the transmitting terminal, the serial number A response indicating whether or not to perform packet transmission / reception using the SN is returned.

  Therefore, the wireless terminal 1 as a receiving terminal is also given an opportunity to return a reply as to whether or not to perform packet transmission / reception using the serial number SN.

  Further, in the wireless communication method of the present embodiment, as a result of confirming the reply whether or not the wireless terminal 1 as the transmitting terminal performs packet transmission / reception using the serial number SN from the wireless terminal 1 as the receiving terminal, When the wireless terminal 1 as the receiving terminal refuses to perform packet transmission / reception using the serial number SN, communication is performed using a packet transmission / reception system that does not use the serial number SN used in Bluetooth.

  Therefore, when the reception side refuses to perform packet transmission / reception, communication is performed using a packet transmission / reception method that does not use the serial number SN used in Bluetooth.

  Further, in the wireless communication method of the present embodiment, when it is confirmed that the wireless terminal 1 as the transmitting terminal performs packet transmission / reception using the serial number SN with the wireless terminal 1 as the receiving terminal, As a method of assigning the number SN, the receiving terminal is requested to perform packet transmission / reception using a packet provided with the serial number field as a part of the payload body.

  Therefore, as a method for assigning the serial number SN, packet transmission / reception can be performed using a packet provided with the serial number field as a part of the payload body.

  In the wireless communication method according to the present embodiment, the wireless terminal 1 as the receiving terminal assigns the serial number field to the head as a part of the payload body as a method of assigning the serial number SN from the wireless terminal 1 as the transmitting terminal. When it is requested to perform packet transmission / reception using the received packet, a response as to whether to approve is returned.

  Therefore, the wireless terminal 1 as the receiving terminal performs the packet transmission / reception by the packet having the serial number field attached to the head as a part of the payload body as a method of assigning the serial number SN from the wireless terminal 1 as the transmitting terminal. If requested, you will be given the opportunity to reply whether to approve.

  Further, in the wireless communication method of the present embodiment, the wireless terminal 1 as a transmitting terminal performs packet transmission / reception by a packet having a serial number field attached to the head as a part of the payload body by the wireless terminal 1 as a receiving terminal. Is accepted, packet transmission / reception by the packet is selected.

  Therefore, the wireless terminal 1 as the transmitting terminal can select packet transmission / reception based on the consent of the wireless terminal 1 as the receiving terminal.

  Further, in the wireless communication method of the present embodiment, when it is confirmed that the wireless terminal 1 as the transmitting terminal performs packet transmission / reception using the serial number SN with the wireless terminal 1 as the receiving terminal, As a method for assigning the number SN, the receiving terminal is requested to perform packet transmission / reception using a packet having a data length area designation field and a serial number field as a part of the payload body.

  Therefore, the wireless terminal 1 as the transmission terminal performs packet transmission / reception using a packet having a data length area designation field and a serial number field as a part of the payload body as a method of assigning the serial number SN. Can be requested from the receiving terminal.

  Further, in the wireless communication method of the present embodiment, the wireless terminal 1 as the receiving terminal has a data length area designation field and a serial number field as a method of assigning the serial number SN from the wireless terminal 1 as the transmitting terminal. When it is requested to perform packet transmission / reception by a packet attached to the head as a part of the payload body, an opportunity to reply whether or not to approve packet transmission / reception by the packet is given.

  Also, in the wireless communication method of the present embodiment, the wireless terminal 1 as the transmitting terminal uses the wireless terminal 1 as the receiving terminal to set the data length area designation field and the serial number field at the beginning as part of the payload body. When it is permitted to perform packet transmission / reception using the assigned packet, packet transmission / reception using the packet is selected.

  Therefore, the wireless terminal 1 as the transmitting terminal can select packet transmission / reception based on the consent of the wireless terminal 1 as the receiving terminal.

  Further, in the wireless communication method of the present embodiment, the wireless terminal 1 as a transmitting terminal performs packet transmission / reception by a packet having a serial number field as a part of the payload body from the wireless terminal 1 as a receiving terminal. In addition, when it is also refused to perform packet transmission / reception by a packet attached to the head of the data length area designation field and the serial number field as part of the payload body, the serial number SN used in Bluetooth is used. Communicate using a packet transmission / reception method.

  Therefore, when the wireless terminal 1 as the transmitting terminal rejects the two methods of the first means and the second means as the serial number assigning method from the wireless terminal 1 as the transmitting terminal, It is possible to perform communication in a packet transmission / reception system that does not use the serial number SN used in Bluetooth, which is the law.

  Data processing such as mobile phones, personal handy phones (PHS), personal computers, personal digital assistants (PDAs), digital cameras, and portable audio devices to which wireless communication systems using Bluetooth are applied Devices can be connected wirelessly and used for data communication in a short-distance network of about 100 m at the maximum.

1 is a timing chart illustrating a data transmission / reception method according to an embodiment of a transmission terminal, a communication terminal, a wireless communication system, and a wireless communication method according to the present invention. It is a flowchart which shows the retransmission procedure in the said radio | wireless communication method. (A) (b) is a block diagram which shows the payload body of the packet used for the said radio | wireless communication method. It is a block diagram which shows the structure of the said transmission terminal and a communication terminal. In the wireless communication method, it is a flowchart showing a processing procedure when applying the serial number method in either the first means and the second means. In the said wireless communication method, it is a flowchart which shows the process sequence at the time of applying a serial number system in a 1st means. It is a flowchart which shows the process sequence at the time of applying a serial number system in a 2nd means in the said radio | wireless communication method. It is a flowchart which shows the communication procedure in the said wireless communication method. It is a figure which shows the structural example of the piconet in the said radio | wireless communications system. It is a block diagram which shows the packet used for the said radio | wireless communication method. It is a block diagram which shows the access code of the packet used for the said wireless communication method. It is a block diagram which shows the packet header of the packet used for the said radio | wireless communication method. It is a block diagram which shows the payload of the packet used for the said radio | wireless communication method. It is a block diagram which shows the structure of the conventional communication terminal. 5 is a timing chart showing a method of transmitting / receiving data to / from each other by a master / slave method in the wireless communication method using the conventional wireless communication system. 6 is a timing chart showing a state in which an error occurs in transmission / reception when data is transmitted / received in a master / slave method in the wireless communication method using the conventional wireless communication system. 6 is a timing chart showing a state in which a packet loss occurs when data is transmitted / received in the master / slave method in the wireless communication method using the conventional wireless communication system.

Explanation of symbols

1 wireless terminal (transmitting terminal, receiving terminal, communication terminal, wireless communication system)
20 wireless communication unit 21 control unit (transmission control means, reception control means, communication control means)
22 Transmission / reception setting unit (number assigning means, data length information obtaining means, serial number obtaining means)
23 Transmitter (Transmission means)
24 Receiving part (receiving means)
27 Interface section (interface means)
31 CPU
32 ROM
33 RAM
ARQN retransmission control information SEQN retransmission control information SN serial number

Claims (28)

In a transmission terminal comprising an interface means for connecting to a host device, and transmitting data to a reception terminal in units of packets using radio,
Transmitting means for transmitting a packet having retransmission control information, which is information for confirming the consistency of the data, in a packet header ;
Numbering means for giving a serial number to a packet to be transmitted;
And a transmission control means for controlling the operation of said transmitting means and number providing means,
The numbering means is
A transmitting terminal, characterized in that the serial number is given in a payload body of the packet . The transmission control means includes
When there is no request for retransmission from a receiving terminal that has received a packet, the value of the serial number assigned to the previously sent packet is increased by a certain number and given to the next packet to send the packet. Item 1. The transmission terminal according to Item 1. The transmission control means includes
The serial number assigned to a previously transmitted packet is decremented by a certain number and sent to the next packet when the receiving terminal that received the packet does not request retransmission, and the packet is transmitted. 1. The transmission terminal according to 1. The transmission control means includes
2. The transmitting terminal according to claim 1, wherein when the receiving terminal that has received the packet requests retransmission, the same packet is transmitted without changing the value of the serial number assigned to the previously transmitted packet. The numbering means is
Maximum value determining means for determining the maximum value of the serial number;
2. The transmission terminal according to claim 1, further comprising data length information giving means for giving data length information necessary for storing the determined maximum value of the serial number in the payload body . In a communication terminal that transmits and receives data in units of packets using radio,
Receiving means for receiving a packet transmitted from the transmitting terminal according to claim 1;
From the payload body of the received packet, and the serial number obtaining means for obtaining granted serial number,
A communication terminal comprising: a communication control unit that controls operations of the receiving unit and the serial number acquisition unit. The communication control means includes
The retransmission control information, which is stored in the packet header of the received packet and is information for confirming the consistency of the data, is a content requesting the retransmission to the transmission source, and is given to the received packet. If the serial number is not the value that follows the serial number assigned to a packet received earlier, the communication terminal according to claim 6, wherein the requesting retransmission of the previous packet to the transmission source. The communication control means includes
When the retransmission control information stored in the packet header of the received packet , which is information for confirming the integrity of the data, is the content requesting retransmission to the transmission source, The communication terminal according to claim 6, wherein retransmission of the packet is requested. 7. The communication terminal according to claim 6, further comprising data length information acquisition means for acquiring data length information given in the payload body of the received packet.   A wireless communication system comprising: the transmission terminal according to any one of claims 1 to 5; and the communication terminal according to any one of claims 6 to 9. A wireless communication method using the transmission terminal according to any one of claims 1 to 5 to perform transmission by assigning a serial number in a payload body of a packet. A wireless communication method using the communication terminal according to any one of claims 6 to 9, wherein a serial number is assigned to a payload body of a packet to perform transmission / reception. 12. The wireless communication method according to claim 11 , wherein the serial number assigned to the transmission packet of the transmitting terminal is compared with the serial number assigned to the reply packet from the receiving terminal.   When the serial number given to the reply packet from the receiving terminal is different from the serial number given to the sending packet sent by the sending terminal immediately before, the sending terminal judges that there is an abnormality in reception at the receiving terminal. The wireless communication method according to claim 13, wherein:   15. The wireless communication method according to claim 14, wherein when the transmitting terminal determines that there is an abnormality in reception, the transmitting terminal retransmits a packet having the same content regardless of a retransmission request from the receiving terminal.   The transmitting terminal retransmits the same packet as the packet transmitted immediately before when the serial number assigned to the packet returned from the receiving terminal is the same as the serial number assigned to the packet transmitted immediately before The wireless communication method according to claim 13. The sending terminal confirms the consistency of the above data written in the packet header of the received packet when the serial number given to the packet returned from the receiving terminal is different from the serial number given to the packet sent immediately before 14. The wireless communication method according to claim 13, wherein the previous packet is retransmitted when retransmission control information, which is information for performing transmission, has a value for requesting retransmission to the transmitting terminal. The sending terminal confirms the consistency of the above data written in the packet header of the received packet when the serial number given to the packet returned from the receiving terminal is different from the serial number given to the packet sent immediately before 14. The wireless communication method according to claim 13, wherein the next packet is retransmitted when retransmission control information, which is information for performing transmission, has a value that does not request retransmission to the transmitting terminal. 12. The wireless communication method according to claim 11 , wherein the transmitting terminal requests the receiving terminal to perform packet transmission / reception using a serial number.   20. The reception terminal returns a response as to whether or not to perform packet transmission / reception using the serial number when the transmission terminal is requested to perform packet transmission / reception using the serial number. Wireless communication method.   Used by Bluetooth when the sending terminal refuses to send / receive a packet using the serial number from the receiving terminal as a result of confirming whether or not to send / receive the packet using the serial number from the receiving terminal. 21. The wireless communication method according to claim 20, wherein communication is performed using a packet transmission / reception system that does not use a serial number.   When it is confirmed that the sending terminal transmits / receives a packet using the serial number to / from the receiving terminal, as a method of giving the serial number, the packet by the packet assigned with the serial number field at the head as a part of the payload body 21. The wireless communication method according to claim 20, wherein the receiving terminal is requested to perform transmission / reception.   When the receiving terminal is requested to perform packet transmission / reception by the packet with the serial number field attached to the head as a part of the payload body as a serial number assigning method from the transmitting terminal, the receiving terminal returns a response as to whether or not to approve. 23. The wireless communication method according to claim 22, wherein:   The transmitting terminal selects packet transmission / reception by a packet when the receiving terminal is permitted to perform packet transmission / reception by a packet having a serial number field attached to the head as a part of a payload body. 24. The wireless communication method according to 23.   When it is confirmed that the transmitting terminal performs packet transmission / reception using the serial number with the receiving terminal, as a method of assigning the serial number, the data length area designation field and the serial number field are used as one part of the payload body. 21. The wireless communication method according to claim 20, wherein the receiving terminal is requested to perform packet transmission / reception using a packet attached to the head as a section.   When the receiving terminal is requested by the transmitting terminal to perform packet transmission / reception as a method of assigning a serial number, using a packet with a data length area designation field and a serial number field as a part of the payload body. 26. The wireless communication method according to claim 25, wherein a reply as to whether to approve packet transmission / reception by the packet is made.   When the receiving terminal is permitted to perform packet transmission / reception by a packet having a data length area designation field and a serial number field attached to the head as a part of the payload body by the receiving terminal, the transmission terminal transmits / receives the packet by the packet. 27. The wireless communication method according to claim 26, wherein the wireless communication method is selected.   The sending terminal can perform packet transmission / reception by a packet with the serial number field added to the head as a part of the payload body from the receiving terminal, or the data length area designation field and the serial number field as the head of the payload body. The wireless communication method according to claim 19, wherein, when it is also refused to perform packet transmission / reception with a packet attached to, communication is performed using a packet transmission / reception method that does not use a serial number used in Bluetooth.

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