JP2006019881A - Wireless network communication method and wireless network communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless network communication system for carrying out data communication by each prescribed polling period that can attain data communication in response to a communication state of each slave without the need for determining the precedence of the slaves. <P>SOLUTION: In a cordless phone 1 carrying out communication in a wireless network wherein a transmission slot from a master nit 2 to a slave unit 3 and a return slot from the slave unit 3 to the master unit 2 are assigned by each polling period, the slave unit 3 includes a reception section for receiving a first packet transmitted from the master unit 2 and a transmission section for transmitting for including a communication state with the master unit 2 to a second packet and transmitting the resulting second packet to the master unit 2, and the master unit 2 includes a transmission section for transmitting the first packet to the slave unit 3, a reception section for receiving the second packet returned from the slave unit 3, and a setting section for setting the first and second transmission slots for a succeeding polling period in response to the information included in the second packet and indicating the communication state with the master unit 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless network communication method and a wireless network communication system for performing communication in time-divided slots.

  In recent years, various standards have been standardized for wireless networks, and devices having various applications have been connected to wireless networks of the same standard.

  For example, Bluetooth (Bluetooth (registered trademark)), which is a wireless network standard, connects not only computers but also computer peripherals such as printers and scanners, facsimile devices, audio devices, cordless telephones, and the like according to the Bluetooth standard. it can.

  Bluetooth uses a frequency band from 2.402 GHz to 2.480 GHz called an ISM (Industry Science Medical) band. The Bluetooth communication method employs a frequency hopping spread spectrum method of time division slot multiplexing in which this ISM band is divided into 79 frequency bands into slots of every 625 μs and communication is performed by randomly changing the channel. ing.

  In Bluetooth, a master that is one main device and a slave that is one or more slave devices constitute a network called a piconet.

  The communication between the master and the slave is performed by specifying the address assigned to the slave for polling in which the master confirms whether there is a transmission request to the slave. The slave performs data communication by responding to this polling.

  Data communication by this polling is performed by selecting slaves in order from the master. When polling from the master makes a round of all the slaves, polling is performed in the same order.

  In Bluetooth, the order of polling transmitted from the master to the slave is arbitrary. However, when a communication standard such as Bluetooth is adopted between a master unit serving as a master and a slave unit serving as a slave such as a cordless telephone, a polling order for selecting a slave is determined in advance. This is because when a polling slot destined for the slave device that is transmitted from the master device is determined in advance, the circuit that modifies and demodulates the radio wave only for the time of that slot is activated, thereby reducing the battery life. This is because it can be extended.

  As described above, as a communication method in which slaves are selected in order from the master and polling is performed, there is a communication method described in Patent Document 1 although it is wired communication.

  In the communication method described in Patent Document 1, when the master transmits a transmission permission command, each slave confirms that the master can receive. Thereafter, each slave monitors the presence or absence of a signal on the transmission path.

Then, when other slaves with higher priority are communicating with the master, each slave waits for transmission with the master even if it is the time of its own slot, and other slaves and the master When transmission is not performed between the two, the transmission with the master is performed when the slot becomes its own slot.
JP-A-6-231880

  In the communication method described in Patent Document 1, a slave with a high priority can use a slot of another slave with a low priority to transmit regardless of the state of the master. Depending on the communication state, it can be used up to the slot of another slave having a low priority. Therefore, a large amount of data can be transmitted and received at a time on the slave side.

  However, a transmission slot in which a packet is transmitted from a master such as Bluetooth and a return slot in which a packet is returned from a slave cannot be applied to a predetermined communication standard.

  Further, in the communication method described in Patent Document 1, since the slave priority is higher in the slot in which the slave polling order is earlier, for example, a moving image composed of a plurality of slave units and a master unit When applied to a cordless phone that can display, a slave unit assigned to an address with a high priority will have a smooth moving picture, but a slave unit with a low priority will have a little moving picture. It is assumed that

  Accordingly, the present invention provides a wireless network communication system that performs data communication between a master and a slave at a predetermined polling cycle, and can perform data communication according to the communication state of each slave without determining the priority order on the slave side. An object is to provide a network communication method and a wireless network communication system.

  In the wireless network communication method of the present invention, the transmission slot in which a packet is transmitted from a master to a slave and the reply slot in which a packet is returned from the slave to the master are assigned via the wireless network assigned for each polling cycle. In the wireless network communication method in which a master and the slave communicate, the master transmits a first packet to the slave using the transmission slot; and the slave transmits the first packet transmitted from the master. A step of transmitting a second packet responding to one packet including information indicating a communication state with the master using the reply slot; and the master performs next polling according to the information indicating the communication state. A step for setting the first and second transmission slots to the slave in a cycle. Characterized in that it comprises and.

  The wireless network communication method of the present invention is a wireless network communication system in which data communication is performed between a master and a slave at a predetermined polling cycle, according to the communication state of the master and each slave without determining the priority order on the slave side. Data communication can be enabled.

According to a first aspect of the present invention, a master and a slave are connected via a wireless network in which a transmission slot in which a packet is transmitted from a master to a slave and a return slot in which a packet is returned from the slave to the master are assigned for each polling period. In the wireless network communication method in which communication is performed, the master transmits a first packet to the slave using a transmission slot, and the slave responds to the first packet transmitted from the master. And including information indicating the communication state with the master using the reply slot, and the master sets the first and second transmission slots to the slave in the next polling period according to the information indicating the communication state. And a setting step.

  In a conventional wireless network communication system, polling from a master to a slave is performed at each polling cycle based on information exchanged in advance between a master and a slave using a message. Normally, in devices where current consumption is not a problem, the slave can receive even if the master sends a message to the slave at a timing other than the polling cycle by making all reception slots active. However, in devices where current consumption must be kept low, slaves basically cannot activate slots other than the reception slot of the polling timing, so each slave has one slot set in one polling cycle. There is only. For example, if the polling cycle of all slaves is the same and the polling timing is shifted by two slots and set, the slaves are selected in order from the master and polling is transmitted. When polling from the master makes a round of all the slaves, polling can be performed in the same order. In the present invention, since the master can set a slot in which the master and the slave transmit / receive twice within the polling period according to the information indicating the communication state with the master transmitted from the slave, Communication for error recovery and communication according to the data amount can be performed.

  In addition, since the master sets the slot according to the communication state with the slave, it is not necessary to determine the priority order of each slave.

  In the second invention of the present application, the master transmits the first packet in the first transmission slot in the second transmission slot according to the information indicating the communication error of the first packet, which is information indicating the communication state. The method includes a step of transmitting the third packet to the slave.

  Since the information indicating the communication state is the information indicating the communication error of the first packet transmitted from the master, the first packet transmitted from the master to the slave can be retransmitted within the same polling cycle. The third packet, which is new communication data, can be transmitted from the master to the slave.

  According to the third invention of the present application, the first and second corresponding to the first and second transmission slots according to the information indicating the transmission data amount from the slave to the master, which is the information indicating the communication state. It includes a step of receiving a packet from a slave in a reply slot.

  Since the information indicating the communication status is the information indicating the amount of data transmitted from the slave to the master, the master receives two packets from the slave within the same polling period even when the amount of data transmitted on the slave side increases. Is possible.

  According to a fourth aspect of the present application, a master and a slave are connected via a wireless network in which a transmission slot for transmitting a packet from the master to the slave and a return slot for returning a packet from the slave to the master are assigned for each polling period. In the wireless network communication method for performing communication, the master transmits a first packet to the slave using a transmission slot, and the slave transmits a second packet in response to the first packet transmitted from the master. A step of transmitting using the reply slot; and a step of setting the first and second transmission slots to the slave in the next polling period by the master according to the communication state with the slave. It is.

In a conventional wireless network communication system, polling from a master to a slave is performed at each polling cycle based on information exchanged in advance between a master and a slave using a message. Normally, in devices where current consumption is not a problem, the slave can receive even if the master sends a message to the slave at a timing other than the polling cycle by making all reception slots active. However, in devices where current consumption must be kept low, slaves basically cannot activate slots other than the reception slot of the polling timing, so each slave has one slot set in one polling cycle. There is only. For example, if the polling cycle of all slaves is the same and the polling timing is shifted by two slots and set, the slaves are selected in order from the master and polling is transmitted. When polling from the master makes a round of all the slaves, polling can be performed in the same order. In the present invention, since the master can set a slot in which the master and the slave transmit / receive twice within the polling period according to the information indicating the communication state with the master transmitted from the slave, Communication for error recovery and communication according to the data amount can be performed.

  In addition, since the master sets the slot according to the communication state with the slave, it is not necessary to determine the priority order of each slave.

  According to a fifth aspect of the present application, the master transmits a packet requesting retransmission of the second packet in the first transmission slot in response to a communication error of the second packet in communication with the slave. And a step of transmitting a packet requesting transmission of the fourth packet in two transmission slots.

  Since the communication state with the slave is the communication error of the second packet, the second packet transmitted from the slave to the master can be retransmitted, and the new communication data is updated within the same polling cycle. Four packets can be transmitted from the slave to the master.

  The sixth invention of the present application includes a step in which the master transmits a packet to the slave using the first and second transmission slots according to the amount of data to be transmitted to the slave that is in communication with the slave. It is a feature.

  By setting the amount of data to be transmitted to the slave as the communication state with the slave, even when the amount of data to be transmitted on the master side is increased, packet transmission can be performed twice from the slave to the master within the same polling period.

  According to a seventh aspect of the present invention, a master and a slave are connected via a wireless network in which a transmission slot in which a packet is transmitted from a master to a slave and a return slot in which a packet is returned from the slave to the master are assigned for each polling period. In the wireless network communication system in which the communication is performed, the slave includes in the second packet information indicating a communication state between the receiving unit that receives the first packet transmitted from the master using the transmission slot and the master. Transmitting means for transmitting to the master using a reply slot, the master transmitting means for transmitting the first packet to the slave using the transmission slot, and a second reply sent from the slave using the reply slot. In response to information indicating the communication state between the receiving means for receiving the packet and the master included in the second packet. Te is obtained characterized by a setting means for setting the first and second transmission slot in the next polling cycle.

In a conventional wireless network communication system, polling from a master to a slave is performed at each polling cycle based on information exchanged in advance between a master and a slave using a message. Normally, in devices where current consumption is not a problem, the slave can receive even if the master sends a message to the slave at a timing other than the polling cycle by making all reception slots active. However, in a device that needs to keep current consumption low, the slaves cannot basically activate slots other than the reception slot of the polling timing. Therefore, each slave has one slot set in one polling cycle. There is only. For example, if the polling cycle of all slaves is the same and the polling timing is shifted by two slots and set, the slaves are selected in order from the master and polling is transmitted. When polling from the master makes a round of all the slaves, polling can be performed in the same order. In the present invention, since the master can set a slot in which the master and the slave transmit and receive twice within the polling period according to the information indicating the communication state with the master transmitted from the slave, error recovery is possible. And communication according to the amount of data.

  In addition, since the master sets the slot according to the communication state with the slave, it is not necessary to determine the priority order of each slave.

  In the eighth invention of the present application, the master transmission means transmits the first packet in the first transmission slot according to the information indicating the communication error of the first packet, which is information indicating the communication state, and the second packet. The third packet is transmitted to the slave in the transmission slot.

  By using the information indicating the communication state as the information indicating the communication error of the first packet transmitted from the master, the transmission means of the master can retransmit the first packet transmitted from the master to the slave. In the same polling cycle, the third packet as new communication data can be transmitted from the master to the slave.

  According to a ninth aspect of the present application, the master receiving means has the first and second transmission slots corresponding to the first and second transmission slots according to the information indicating the amount of transmission data from the slave to the master, which is information indicating the communication state. It is characterized in that a packet is received from a slave in two reply slots.

  Since the information indicating the communication state is the information indicating the amount of transmission data from the slave to the master, even when the amount of transmission data increases on the slave side, the receiving means of the master performs twice from the slave within the same polling period. Packet reception is possible.

  A tenth aspect of the present invention is directed to a master and slave via a wireless network in which a transmission slot in which a packet is transmitted from a master to a slave and a return slot in which a packet is returned from the slave to the master are assigned for each polling period. In the wireless network communication system in which the slave communicates, the slave receives a first packet transmitted from the master using a transmission slot, and a second second unit responds to the first packet transmitted from the master. A transmission means for transmitting the second packet, and the master receives the second packet sent back from the slave using the reply slot and the transmission means for sending the first packet to the slave using the transmission slot. The first and second transmission slots are transmitted in the next polling cycle according to the communication state between the receiving means and the slave. It is obtained characterized by a setting means for setting and.

In a conventional wireless network communication system, polling from a master to a slave is performed at each polling cycle based on information exchanged in advance between a master and a slave using a message. Normally, in devices where current consumption is not a problem, the slave can receive even if the master sends a message to the slave at a timing other than the polling cycle by making all reception slots active. However, in devices where current consumption must be kept low, slaves basically cannot activate slots other than the reception slot of the polling timing, so each slave has one slot set in one polling cycle. There is only. For example, if the polling cycle of all slaves is the same and the polling timing is shifted by two slots and set, the slaves are selected in order from the master and polling is transmitted. When polling from the master makes a round of all the slaves, polling can be performed in the same order. In the present invention, since the master can set a slot in which the master and the slave transmit and receive twice within the polling period according to the information indicating the communication state with the master transmitted from the slave, error recovery is possible. And communication according to the amount of data.

  In addition, since the master sets the slot according to the communication state with the slave, it is not necessary to determine the priority order of each slave.

  In an eleventh aspect of the present invention, the master transmission means transmits a packet requesting retransmission of the second packet in the first transmission slot in response to a communication error of the second packet that is in communication with the slave. Then, a packet requesting transmission of the fourth packet is transmitted in the second transmission slot.

  Since the communication state with the slave is the communication error of the second packet, the master transmission means. The second packet transmitted from the slave to the master can be retransmitted, and the fourth packet, which is new communication data, can be transmitted from the slave to the master within the same polling period.

  In a twelfth aspect of the present invention, the master transmission means transmits the packet to the slave using the first and second transmission slots according to the amount of data transmitted to the slave that is in communication with the slave. It is characterized by.

  Since the communication state with the slave is set to the amount of data to be transmitted to the slave, the master transmitting means allows the packet from the slave to the master within the same polling cycle even when the amount of data to be transmitted on the master side increases. Transmission is possible.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram for explaining a cordless telephone comprising a master unit as a master and a slave unit as a slave as an embodiment of a wireless network communication system according to the present invention.

  In the example of the cordless telephone 1 shown in FIG. 1, a wireless network having the master unit 2 as a master is formed, and the six slave units 3 (3a to 3f) as slaves can be connected to the master unit 2 as a master by radio. Be in range. If it complies with the Bluetooth specification, this wireless network is called a piconet. The cordless telephone 1 shown in FIG. 1 communicates between the parent device 2 and the child devices 3a to 3f with packets conforming to the Bluetooth specification.

  The base unit 2 is connected to the public line network 5 via a wired transmission line 4 and can talk to the other party via the public line network 5. Further, although not shown, the base unit 2 is connected to the Internet via a LAN (Local Area Network). The cordless handsets 3a to 3f of the cordless telephone 1 are devices capable of transmitting and receiving not only voice but also moving images.

Next, the configuration of master device 2 as a master will be described with reference to FIG. FIG. 2 is a diagram for explaining the configuration of the base unit of the cordless telephone that is an example of the wireless network communication system according to the embodiment of the present invention. In FIG. 2, for the sake of convenience, only the main components are shown, and the base unit 2 omits means for connecting to the public line network 5 via the transmission line 4.

  In FIG. 2, the base unit 2 includes a radio unit 10, an antenna 11, a synchronous correlator 12, a received packet analysis unit 13, a received packet processing unit 14, a received image data buffer 15, and a transmitted image data buffer 16. A transmission packet creation unit 17 and a communication control unit 18.

  The wireless unit 10 communicates with an electronic device connected to a wireless network by demodulating a radio wave received from an antenna 11 that protrudes from the casing and modulates a radio wave transmitted to the antenna 11. I do. The radio unit 10 uses a frequency band from 2.402 GHz to 2.480 GHz called an ISM band, and modulates and demodulates, for example, by a wave number modulation method (Frequency Shift Keying) or a phase modulation method (Phase Shift Keying). To do.

  The synchronous correlator 12 determines whether or not the packet is from a legitimate partner (slave 3) belonging to the same wireless network, based on the access code that is the head portion of the packet conforming to Bluetooth. If the synchronous correlator 12 determines that the received packet is a packet of the same wireless network, the synchronous correlator 12 outputs the received packet to the received packet analysis unit 13. The synchronization correlator 12 checks a synchronization error that occurs in a preamble, sync word, trailer, or the like included in the access code, and notifies the communication control unit 18 when an error occurs.

  The received packet analysis unit 13 analyzes a common packet used for establishing synchronization in a wireless network, an SCO packet used for synchronous communication, an ACL packet used for asynchronous communication, and the like. The received packet analysis unit 13 checks an 8-bit error detection code (HEC) included in the packet header, and notifies the communication control unit 18 when an error occurs.

  The received packet processing unit 14 separates the data stored in the payload, and stores it in the received image data buffer 15 when the received packet is image data. The received packet processing unit 14 checks the 16-bit CRC included in the payload, and notifies the communication control unit 18 when an error occurs, and discards the packet according to the degree of error occurrence.

  The received image data buffer 15 is a storage means for storing received image data, and has a capacity of 2 MB. The transmission image data buffer 16 is a storage means for storing moving image data or a moving image file input from an input means such as a video camera (not shown), and has a capacity of 2 MB.

  The transmission packet creation unit 17 creates a packet based on the output of the transmission image data buffer 16 based on the output of the transmission image data buffer 16 and the audio data or the moving image data input from the microphone or the camera, and outputs them to the radio unit 10. The transmission packet creation unit 17 has a function of inputting data for sending synchronization establishment packets and notifying various information from the communication control unit 18 described later, and outputting the data to the wireless unit 10.

  The communication control unit 18 includes moving image data stored in the transmission image data buffer 16, an access code for establishing synchronization used for communication, information indicating a communication error that is information indicating a communication state, and transmission data. A transmission packet creation unit 17 generates information indicating the amount, a packet header including information such as an SCO packet used for synchronous communication, an ACL packet used for asynchronous communication, a CRC used for payload error detection, and the like. Output to.

  Hereinafter, the communication control unit 18 will be described in detail.

  The communication control unit 18 includes a reception unit 18a, a transmission unit 18b, and a setting unit 18c. The receiving unit 18a controls the radio unit 10, the synchronous correlator 12, the received packet processing unit 13, and the received packet processing unit 14 to receive a packet returned from the slave using a return slot. Means. The received moving image data is input from the received image buffer 15 and output to the public network 5 via the transmission path 4.

  The transmission unit 18b is a transmission unit that transmits the moving image data in the transmission image data buffer 16 as a packet by using the transmission slot transmitted by the master by controlling the radio unit 10 and the transmission packet creation unit 17. .

  The setting unit 18c includes a slot of a packet to be retransmitted in the next polling period according to information indicating a communication error, which is information indicating a communication state included in a packet returned from the slave, and information indicating a transmission data amount, This is setting means for setting a slot for transmitting the next data. In addition, the setting unit 18c performs the first and second polling cycles in the next polling cycle according to the communication error of the packet received from the child device 3 that is in the communication state with the child device 3 and the amount of transmission data to the child device 3. Set the transmission slot.

  Next, the configuration of the cordless handset 3 as an example of the wireless network communication system according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a diagram for explaining the configuration of the cordless telephone handset that is an example of the wireless network communication system according to the embodiment of the present invention. In FIG. 3, a radio unit 10, an antenna 11, a synchronous correlator 12, a received packet analysis unit 13, a received packet processing unit 14, a received image data buffer 15, a transmitted image data buffer 16, and a transmitted packet creation unit 17 are shown in FIG. 2 have the same functions as those in FIG. The handset 3 includes a microphone, a speaker, an input means such as a telephone number, and a display means for displaying the telephone number, but is not shown in FIG. 3 for convenience of explanation.

  In FIG. 3, the communication control unit 19 includes a receiving unit 19a and a transmitting unit 19b. The receiving unit 19a controls the radio unit 10, the synchronous correlator 12, the received packet processing unit 13, and the received packet processing unit 14, thereby transmitting a packet transmitted using a transmission slot transmitted from the master. It is a receiving means for receiving. The received moving image data is input from the received image buffer 15 and output to display means such as a screen.

  The transmission unit 19b of the communication control unit 19 controls the wireless unit 10 and the transmission packet creation unit 17, thereby using a reply slot that is a slot that responds to the transmission slot transmitted by the master. The moving image data is returned to the master. Further, at this time, it is a transmission means for sending back information to the master including information indicating the reception state of the packet from the master in the packet.

  Based on FIG. 4, the format of a packet transmitted and received between base unit 2 and handset 3 of the cordless telephone which is an example of the wireless network communication system according to the embodiment of the present invention configured as described above. explain. FIG. 4 is a diagram for explaining the format of a packet used in the wireless network communication system according to the embodiment of the present invention.

As shown in FIG. 4, a packet is basically composed of three parts: an access code that is a head part, a packet header that is an intermediate part, and a payload that is a final part. The access code therein is a synchronization establishment field in which basic information indicating a packet transmission destination or piconet is stored. The packet header is a field for communication control when performing communication. The payload is a data field in which user data used between electronic devices is stored.

  Next, the contents of the packet header will be described in detail according to the Bluetooth specification.

  The packet header is composed of AM_ADDR, TYPE, FLOW, ARQN, SEQN, and HEC.

  AM_ADDR in this packet header is a field that is composed of 3 bits and stores an identifier for identifying a counterpart wireless network communication device in a piconet called an active member address. From the master device 2 which is the master, the other party of polling is designated by the information written in this AM_ADDR.

  TYPE in the packet header is composed of 4 bits and is a packet type type field that defines whether the packet is an SCO packet or an ACL packet.

  The FLOW in the packet header is composed of 1 bit and is used for flow control of packets transmitted and received. In other words, when the slave handset 3 is full of the reception image data buffer 15 for reception, the master stops sending the received image data by setting FLOW “0” and returning the packet. Can be requested.

  The ARQN in the packet header is composed of 1 bit, and is a field for notifying the parent device 2 which is the packet transmission source of whether or not an error has occurred in the packet received by the child device 3, and the parent device of the packet transmission source. 2 performs control such as retransmission using this field.

  The SEQN in the packet header is a management field that is composed of 1 bit and prevents the retransmitted packets from being duplicated. The wireless network communication apparatus that transmits a packet toggles and transmits the SEQN every time it is retransmitted. Since SCO packets cannot be retransmitted in the same manner as ARQN, SEQN is not used, so 0 is set at the time of transmission and is ignored at the time of reception.

  The HEC in the packet header is composed of 8 bits, and is a field for storing error detection codes for a total of 10 bits of AM_ADDR, TYPE, FLOW, ARQN, and SEQN.

  Thus, the packet header in Bluetooth is defined.

  Next, the operation of the cordless telephone as an example of the wireless network communication system according to the embodiment of the present invention will be described with reference to FIGS. 5 to 8 are diagrams for explaining the operation of the cordless telephone which is an example of the wireless network communication system according to the embodiment of the present invention. FIG. 9 is a flowchart for explaining the reception operation of the master unit that is the master. FIG. 10 is a flowchart for explaining the transmission operation of the parent device. FIG. 11 is a flowchart for explaining the reception operation of the slave slave unit. FIG. 12 is a flowchart for explaining the transmission operation of the slave.

  First, an operation when a packet transmitted from the parent device 2 to the child device 3a results in a communication error will be described with reference to FIG.

In FIG. 5, Tpol is a period in which the master unit 2 as a master polls the slave units 3 (3a to 3f). In the example of FIG. 5, this polling cycle Tpol is set to 12 slots, and the master unit 2 as a master transmits a polling packet to the slave units 3 (slave units 3a to 3f) every 12 slots. When there are six slave units, polling is performed in the order of the slave units 3a to 3f, but in FIG. 5, only polling for one slave unit is shown for convenience of explanation.

  A combination of a transmission slot in which a packet is transmitted from the parent device 2 to the child device 3 by polling and a reply slot to be returned from the child device 3 to the parent device 2 is the transmission / reception of each child device (child devices 3a to 3f). The receiving slots are shifted by 2 slots so that the receiving slots do not overlap. That is, the 12-slot polling cycle Tpol is set so that the six slave units from the slave unit 3a to the slave unit 3f can make one round.

  The parent device 2 performs polling or transmission of moving image data using a transmission slot at a polling timing set for each of the child devices (child devices 3a to 3f) for each polling cycle. The polling interval and polling timing of the slave unit 3 are arbitrary in Bluetooth, and are determined by settings stored in the setting unit 18c of the communication control unit 18 of the master unit 2. The base unit 2 notifies the handset 3 of this polling cycle and polling timing.

  In this way, the base unit 2 determines the polling cycle and polling timing of the handset 3 in advance and notifies the handset 3 so that the handset 3 can transmit wireless power with high power consumption only during the allocated slot time. Battery life can be extended by making the part 10 into an active state. This control is performed when the communication control part 19 of the subunit | mobile_unit 3a designates the radio | wireless part 10 as an active state or an inactive state.

  Next, a description will be given in order based on FIG.

  First, a packet indicating polling, which is a first packet, is transmitted from the parent device 2 using the slot 2 which is a transmission slot. This is performed by the transmission unit 18b of the communication control unit 18 of the parent device 2 instructing the transmission packet creation unit 17 to create a polling packet addressed to the child device 3a and transmitting the packet via the wireless unit 10. In this case, FLOW and ARQN of the packet header are transmitted as FLOW “0” and ARQN “1”.

This polling is determined by the wireless unit 10 of the slave unit 3a and the synchronous correlator 12 to be a packet addressed to the slave unit 3a. Then, the received packet analysis unit 13 analyzes that the packet is a polling packet and notifies the communication control unit 19 of it.
At this time, if a communication error has occurred, the communication correlator 12, the received packet analysis unit 13, and the received packet processing unit 14 check each field of the packet to detect the communication error.

  In order to respond to the polling using the slot 2, the slave unit 3a returns the moving image data, which is the second packet, as a packet using the slot 3, which is a reply slot. This is performed by the transmission unit 19b of the communication control unit 19 of the slave unit 3a instructing the transmission packet creation unit 17 to transmit the moving image data in the transmission image data buffer 16.

  At that time, the transmission unit 19b of the child device 3a returns information indicating the reception state of the packet received in the slot 2 as FLOW and ARQN of the packet header. In the example shown in FIG. 5, since there is no communication error in the packet received in slot 2, the transmission unit 19b returns FLOW and ARQN of the packet header as FLOW “0” and ARQN “1”.

  Here, since the polling cycle for the slave unit 3a is 12 slots, the next polling slot to be received is 12 slots after the slot that received the polling. That is, next, the slots in which the parent device 2 and the child device 3a communicate with each other are the slot 14 and the slot 15 after 12 slots which are polling cycles.

  When a packet for transmitting moving image data addressed to the child device 3a from the parent device 2 in this slot 14 results in a communication error, the transmission unit 19a of the child device 3a in slot 15 changes the FLOW and ARQN of the packet header. It returns as FLOW “0” and ARQN “0”. The meaning of notifying that there is a communication error in the previous received packet is defined in “0” of this ARQN.

  Receiving unit 18a of base unit 2 that has received this packet header notifies setting unit 18c that a communication error has occurred. In response to this notification, the setting unit 18c of the base unit 2 transmits the first slot in which the packet is retransmitted between the slot 26 and the slot 37, which is the next polling cycle, and the moving image data that should originally be transmitted in this polling cycle. To the second slot for transmitting. That is, the slot 26 is set as a slot for retransmitting the packet transmitted in the previous slot 14, and the slot 28 as the next transmission slot is set as a slot for transmitting a new moving image data packet to be originally transmitted in this cycle. Set.

  Based on the slot setting by the setting unit 18c, the transmission unit 18b retransmits the packet transmitted in the slot 14 in the slot 26 and transmits a new moving image data packet in the slot 28.

  Base unit 2 transmits FLOW as “1” and ARQN “1” as the packet header of slot 26 for retransmitting the packet. The meaning of notifying that it is necessary to increase transmission / reception is defined in “1” of FLOW. Accordingly, the slave unit 3a can recognize that the packet received in the slot 26 is a retransmission packet, and that a new moving image data packet to be originally transmitted in this period is transmitted in the slot 28.

  In the present embodiment, the next transmission slot of the transmission slot used for retransmission is a slot for transmitting new moving image data. However, any slot can be used as long as it is a transmission slot up to slot 37 which is a polling cycle. May be used.

  Next, an operation when the amount of moving image data from the child device 3a to the parent device 2 increases will be described with reference to FIG. As shown in FIG. 6, the slots 2 to 13 are the same as those in FIG.

  In slot 14, polling is transmitted from the parent device 2 to the child device 3a.

  In the slot 15, the transmission unit 19b of the slave unit 3a has such a data amount that the moving image data stored in the transmission image data buffer 16 cannot be transmitted by one packet transmission set within the polling cycle. If it is determined, FLOW is transmitted as “1” and ARQN is transmitted as “1”. The meaning of notifying that it is necessary to increase transmission / reception is also defined in “1” of this FLOW.

Receiving unit 18a of base unit 2 that has received this packet header notifies setting unit 18c that the amount of data will increase. In response to this notification, the setting unit 18c sets the first slot and the second slot in order to cope with the increased data amount between the slot 26 and the slot 37, which is the next polling cycle. In other words, communication between master and slave is 1
Two packets can be communicated at a polling cycle.

  The slave unit 3a can transmit the packet storing the moving image data in the two return slots of the slot 27 and the slot 29, so that an overrun or the like can be prevented in advance. Therefore, the motion of the moving image can be made smooth.

  When the data amount from the child device 3a to the parent device 2 returns to normal, the child device 3a sets the packet transmitted in the slot 39 to FLOW as “0” and ARQN as “1” to the parent device 2. Send.

  Next, an operation when a packet transmitted from the child device 3a to the parent device 2 causes a communication error will be described with reference to FIG. As shown in FIG. 7, the slots 2 to 13 are the same as those in FIG.

  In the slot 14, polling is transmitted from the parent device 2 to the child device 3a.

  The moving image data is transmitted from the child device 3 a to the parent device 2 in the slot 15. If a packet for transmitting moving image data addressed to the parent device 2 from the child device 3a in this slot 15 results in a communication error, the setting unit 18c of the parent device 2 requests retransmission of the packet at the next polling cycle. A slot 26, which is a first slot for performing transmission, and a slot 28, which is a second slot for transmitting moving image data to be originally transmitted in this polling cycle, are set. In slot 26, transmission unit 18a of base unit 2 transmits a packet header indicating a packet retransmission request with FLOW set to “1” and ARQN “0”.

  The receiving unit 19a of the slave unit 3a that has received the packet header prepares that the packet is transmitted from the master unit 2 in the slot 28, and retransmits the packet transmitted in the slot 15 in the slot 27. Notify the transmitter 19b.

  The handset 3a retransmits the packet transmitted in the slot 15 in the slot 27. In addition, the reception unit 19 a notifies the radio unit 10 to set the active state in which the packet from the parent device 2 can be received in the slot 28.

  Then, the transmission unit 19b transmits the moving image data to be transmitted in this polling cycle to the parent device 2 in the slot 29.

  Next, an operation when the amount of moving image data from the parent device 2 to the child device 3a increases will be described with reference to FIG. As shown in FIG. 8, the slots 2 to 13 are the same as those in FIG.

  In the slot 14, the transmission unit 18b of the base unit 2 has a data amount that the moving image data stored in the transmission image data buffer 16 cannot be sent by one packet transmission set within the polling cycle. If it is determined, FLOW is transmitted as “1” and ARQN is transmitted as “1”.

  The receiving unit 19a of the slave unit 3a that has received this packet header prepares that a packet is transmitted from the master unit 2 in the slot 16. Then, in the slot 15, a response packet to the packet transmitted from the parent device 2 in the slot 14 is transmitted. The packet header of the packet of the slot 15 transmits FLOW as “0” and ARQN “1” because the communication error or the like does not occur in the packet of the slot 14.

  In the slot 16, the second packet is transmitted from the parent device 2 to the child device 3a in this polling cycle. In slot 17, a response packet to the packet transmitted from base unit 2 in slot 16 is transmitted.

  When the data amount from the parent device 2 to the child device 3a returns to normal, the packet transmitted in the slot 26 is transmitted to the child device 3a with FLOW set to “0” and ARQN set to “1”.

  Next, the operation of the master unit that is the master of the cordless telephone that is an example of the wireless network communication system according to the embodiment of the present invention will be described with reference to FIGS.

  First, the procedure of the receiving operation of the base unit 2 will be described with reference to FIG.

  As shown in FIG. 9, the parent device 2 determines whether or not a packet has been received from the slave child device 3 (S101).

  When the packet from the handset 3 is not received in S101, the ARQN of the next packet to be transmitted is set to “0” and the reception operation is terminated (S102).

  When a packet from the child device 3 is received in S101, it is determined whether or not the FLOW of the packet header of the packet transmitted in the previous transmission slot is “1”, and the FLOW is “0”. In this case, the process proceeds to S105 (S103).

  If the FLOW is “1” in S103, the setting unit 18c sets the next transmission slot to transmit to the same slave unit 3, and the process proceeds to S105 (S104).

  It is determined whether or not a communication error has occurred upon reception of the packet from the handset 3 (S105).

  If a reception error has occurred, FLOW and ARQN of the next packet transmitted to the same handset 3 are transmitted with FLOW set to “1” and ARQN set to “0” (S106).

  If no reception error has occurred in S105, it is determined whether or not the FLOW of the received packet is “1” (S107).

  If FLOW is not “1” in S107, it is determined whether or not the ARQN of the received packet is “0” (S108).

  If the ARQN is not “0” in S108, the FLOW and ARQN of the next packet transmitted to the same handset 3 are set to “0”, and the ARQN is set to “1” for transmission (S109). .

  When FLOW is “1” in S107 or ARQN is “0” in S108, FLOW and ARQN of the next packet transmitted to the same slave unit 3 are set to “1”. , ARQN is set to “1” and transmitted (S110).

  Next, the procedure of the transmission operation of base unit 2 will be described with reference to FIG. The transmission operation of the base unit 2 is performed subsequently to the reception operation shown in FIG. That is, the packet is received in the reply slot from the slave unit 3, and the master unit 2 transmits the packet in the transmission slot.

As shown in FIG. 10, the parent device 2 determines whether or not the amount of data transmitted to the child device 3 is large. This is a method for avoiding a delay in image transmission caused by an increase in the amount of image data to be transmitted, and updating of the image in real time. The determination is made using the amount of image data to be transmitted as 4 Kbytes as a threshold value. Is going. This 4 Kbyte (32 Kbit) is the data amount of one frame of an I picture used for moving image data such as MPEG (Moving Picture Experts Group) format. Normally, the P picture and B picture are much smaller than this data amount, but when the image change is large, the frame data of a plurality of P pictures may have a data amount as high as 32 Kbits. Since moving image data is real-time data generally called streaming, it needs to be transmitted without delay. In particular, an I picture is transmitted in the same or similar time as a P / B picture even though the data amount of one frame is large. It is required to be done. Therefore, it is determined whether or not the amount of transmission data is large, and transmission is performed using two slots (S120).

  In S120, if the base unit 2 determines that the amount of transmission data to the handset 3 is large and the image cannot be updated in real time, the base unit 2 proceeds to S121 and the transmission unit 18b of the base unit 2 sets the next transmission slot. Is set to transmit FLOW of the packet at “1”.

  If the base unit 2 determines in S120 that the amount of data to be transmitted to the handset 3 is at a level at which an image can be updated in real time, the base unit 2 proceeds to S122 and receives from the handset 3 in the previous reply slot. It is determined whether the FLOW of the received packet is “1”.

  In S122, when the FLOW of the packet received from the slave unit 3 in the previous reply slot is “1”, the process proceeds to S121, and the transmitting unit 18b of the master unit 2 transmits the FLOW of the packet in the next transmission slot. Set to transmit as “1”.

  When the FLOW setting is completed in S121 or S123, the transmission unit 18b of the base unit 2 sets the ARQN of the packet in the next transmission slot. This is because the ARQN is set to “0” when a communication error has occurred in the packet transmitted using the reply slot from the previous slave unit 3, and the ARQN is set to “1” otherwise. Is performed by the transmission unit 18b (S124).

  Next, the operation of the slave unit that is the slave of the cordless telephone that is an example of the wireless network communication system according to the embodiment of the present invention will be described based on FIG. 11 and FIG.

  First, the procedure of the reception operation of the slave unit 3 will be described with reference to FIG.

  As shown in FIG. 11, the slave unit 3 determines whether or not a packet from the master unit 2 as a master has been received (S131).

  If the packet from the parent device 2 is not received in S131, the reception operation of the child device 3 is terminated.

  If a packet is received from the parent device 2 in S131, it is determined whether or not the FLOW of the received packet is “1” (S132).

  If the FLOW of the packet received from the parent device 2 is “1” in S132, the polling or data transfer packet from the parent device 2 is also transmitted to the next slot. The process proceeds to the transmission operation of the slave unit 3 as a slave (S133).

If the FLOW of the packet received from the parent device 2 is “0” in S132, it is determined whether or not the packet transmitted from the parent device 2 has caused a communication error (S134).

  If a communication error has occurred in S134, the ARQN of the packet to be transmitted in the next reply slot is returned as “0”, and the process proceeds to the transmission operation of slave unit 3 that is a slave (S135).

  If no communication error has occurred in S134, the ARQN of the packet to be transmitted in the next reply slot is returned as “1”, and the process proceeds to the transmission operation of the slave unit 3 that is the slave (S136).

  Next, the procedure of the transmission operation of the slave unit 3 will be described with reference to FIG.

As shown in FIG. 12, the slave unit 3 determines whether or not the amount of transmission data to the master unit 2 is large. This is a determination as to whether transmission is possible with one packet, and determination is performed using 4 KB as a threshold. This 4 Kbyte (32 Kbit) is MPEG (Moving Picture Experts)
(Group) format or the like is a data amount of one frame of an I picture used for moving image data. Normally, the P picture and B picture are much smaller than this data amount, but when the image change is large, the frame data of a plurality of P pictures may have a data amount as high as 32 Kbits. Since moving image data is real-time data generally called streaming, it needs to be transmitted without delay. In particular, an I picture is transmitted in the same or similar time as a P / B picture even though the data amount of one frame is large. It is required to be done. Therefore, it is determined whether or not the amount of transmission data is large, and transmission is performed using two slots (S141).

  In S141, if the slave unit 3 determines that the amount of transmission data to the master unit 2 is large and the image cannot be updated in real time, the transmission unit 19b of the slave unit 3 causes the FLOW of the packet in the next transmission slot. Is set to be transmitted as “1” (S142).

  In S141, when the slave unit 3 determines that the amount of data transmitted to the master unit 2 is at a level at which an image can be updated in real time, the transmission unit 19b of the slave unit 3 transmits a packet in the next transmission slot. Is set to transmit as “0” (S143).

  The transmission part 19b of the subunit | mobile_unit 3 sets ARQN of the packet in the next transmission slot. This is because the ARQN is set to “0” when a communication error has occurred in the packet transmitted using the transmission slot from the previous base unit 2, and the ARQN is set to “1” otherwise. Is performed by the transmission unit 19b (S144).

  When the base unit 2 transmits a packet to the same slave unit 3 using the next transmission slot, the packet from the base unit 2 is transmitted to the slave unit 3 in a slot that is not a transmission slot normally used. The Therefore, since it is necessary to perform a reception operation of a packet transmitted from the parent device 2, the process proceeds to a slave reception operation (see FIG. 11) (S145).

  In S145, when there is no packet transmission from the parent device 2 to the same child device 3 using a continuous transmission slot, the child device 3 sets a slot in which polling is transmitted from the next parent device 2. In the present embodiment, 12 slots are set (S146).

  The embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment, and two reply slots are allocated to the slave in one polling cycle. A poll may be transmitted from the master to the slave so as to allocate three or more reply slots.

  Since the present invention can enable data communication according to the communication state of each slave without determining the priority order on the slave side, a wireless network that performs data communication between a master and a slave every predetermined polling period Suitable for communication systems.

The figure explaining the radio | wireless network communication system which concerns on embodiment of this invention The figure explaining the structure of the main | base station of the cordless telephone which is an example of the wireless network communication system which concerns on embodiment of this invention The figure explaining the structure of the subunit | mobile_unit of the cordless telephone which is an example of the radio | wireless network communication system which concerns on embodiment of this invention The figure explaining the format of the packet used for the radio | wireless network communication system which concerns on embodiment of this invention The figure explaining operation | movement of the cordless telephone which is an example of the radio | wireless network communication system which concerns on embodiment of this invention The figure explaining operation | movement of the cordless telephone which is an example of the radio | wireless network communication system which concerns on embodiment of this invention The figure explaining operation | movement of the cordless telephone which is an example of the radio | wireless network communication system which concerns on embodiment of this invention The figure explaining operation | movement of the cordless telephone which is an example of the radio | wireless network communication system which concerns on embodiment of this invention Flowchart for explaining the receiving operation of the master unit as a master Flow chart for explaining the transmission operation of the parent device Flowchart explaining reception operation of slave unit as slave Flowchart explaining transmission operation of slave unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cordless telephone 2 Base | base station 3,3a-3f Slave | mobile_unit 10 Radio | wireless part 11 Antenna 12 Synchronous correlator 13 Reception packet analysis part 14 Reception packet processing part 15 Reception image data buffer 16 Transmission image data buffer 17 Transmission packet creation part 18, 19 Communication control unit 18a, 19a Reception unit 18b, 19b Transmission unit 18c Setting unit

Claims (12)

The master and the slave communicate with each other via a wireless network in which a transmission slot for transmitting a packet from the master to the slave and a return slot for returning a packet from the slave to the master are assigned at every polling period. In a wireless network communication method,
The master transmitting a first packet to the slave using the transmission slot;
The slave transmits a second packet responding to the first packet transmitted from the master, including information indicating a communication state with the master using the reply slot;
And a step in which the master sets first and second transmission slots to the slave in a next polling period in accordance with information indicating the communication state. In response to information indicating a communication error of the first packet, which is information indicating the communication state, the master transmits the first packet in the first transmission slot and the third packet in the second transmission slot. The wireless network communication method according to claim 1, further comprising a step of transmitting the packet to the slave. First and second reply slots corresponding to the first and second transmission slots according to information indicating a transmission data amount from the slave to the master, which is information indicating the communication state of the master. The wireless network communication method according to claim 1, further comprising: receiving a packet from the slave. The master and the slave communicate with each other via a wireless network in which a transmission slot for transmitting a packet from the master to the slave and a return slot for returning a packet from the slave to the master are assigned at every polling period. In a wireless network communication method,
The master transmitting a first packet to the slave using the transmission slot;
The slave transmits a second packet responding to the first packet transmitted from the master using the reply slot;
And a step in which the master sets first and second transmission slots to the slave in a next polling period in accordance with a communication state with the slave. The master transmits a packet requesting retransmission of the second packet in the first transmission slot in response to a communication error of the second packet that is in a communication state with the slave. The wireless network communication method according to claim 1, further comprising a step of transmitting a packet requesting transmission of the fourth packet in the transmission slot. The master includes a step of transmitting a packet to the slave using the first and second transmission slots according to a transmission data amount to the slave that is in a communication state with the slave. The wireless network communication method according to claim 1 or 2. The master and the slave communicate with each other via a wireless network in which a transmission slot for transmitting a packet from the master to the slave and a return slot for returning a packet from the slave to the master are assigned at every polling period. In a wireless network communication system,
The slave receives a first packet transmitted from the master using the transmission slot;
Transmission means including information indicating a communication state with the master in a second packet and transmitting the information to the master using the reply slot;
The master, transmitting means for transmitting the first packet to the slave using the transmission slot;
Receiving means for receiving the second packet returned from the slave using the reply slot;
Wireless network communication comprising: setting means for setting the first and second transmission slots in the next polling period in accordance with information indicating a communication state with the master included in the second packet system. The master transmission means sends the first packet in the first transmission slot to the second transmission slot according to information indicating a communication error of the first packet, which is information indicating the communication state. 8. The wireless network communication system according to claim 7, wherein the third packet is transmitted to the slave. The master receiving means has first and second corresponding to the first and second transmission slots according to information indicating the amount of data transmitted from the slave to the master, which is information indicating the communication state. 9. The wireless network communication system according to claim 7, wherein a packet is received from the slave in a reply slot. The master and the slave communicate with each other via a wireless network in which a transmission slot for transmitting a packet from the master to the slave and a return slot for returning a packet from the slave to the master are assigned at every polling period. In a wireless network communication system,
The slave receives a first packet transmitted from the master using the transmission slot;
Transmitting means for transmitting a second packet in response to the first packet transmitted from the master;
The master, transmitting means for transmitting the first packet to the slave using the transmission slot;
Receiving means for receiving the second packet returned from the slave using the reply slot;
A wireless network communication system comprising: setting means for setting the first and second transmission slots in the next polling period in accordance with a communication state with the slave. The master transmission means transmits a packet requesting retransmission of the second packet in the first transmission slot in response to a communication error of the second packet that is in a communication state with the slave, and 11. The wireless network communication system according to claim 10, wherein a packet requesting transmission of the fourth packet is transmitted in the second transmission slot. The master transmission means transmits a packet to the slave using the first and second transmission slots according to the amount of data transmitted to the slave that is in a communication state with the slave. The wireless network communication system according to claim 10 or 11.

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