JP2009206848A - Wireless communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication device which supports three or more types of wireless communication methods and controls the effect of radio interference to wireless communication methods related to real-time data transmission and reception. <P>SOLUTION: If it is determined that data which is transmitted and received through WLAN wireless communication 200 can be also transmitted and received through BT wireless communication 400 during DCL wireless communication 500 (S26:Yes), a switching request signal is transmitted to a PC 61 to request the data transmission and reception by switching from the WLAN wireless communication 200 to the BT wireless communication 400 (S27). The BT wireless communication 400 and the DCL wireless communication 500 are performed by a frequency hopping method, so that the possibility that radio interference occurs between them is decreased. Thereby, the effect of radio interference due to data transmission and reception can be reduced in the DCL wireless communication 500. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus.

  2. Description of the Related Art Conventionally, communication devices that perform data communication or telephone call via wireless communication are known. In this type of communication device, there are cases where frequency bands used in wireless communication overlap even if the communication method of wireless communication used for data communication or telephone call is different.

  For example, a wireless LAN (hereinafter referred to as “WLAN (Wireless Local Area Network)”) for data communication or the like, Bluetooth (registered trademark, hereinafter referred to as “BT”), a digital cordless telephone ( Hereinafter, “DCL (Digital Cordless)” all use the same frequency band of 2.4 GHz band.

  Here, frequency bands and frequency channels used in WLAN, BT, and DCL will be described with reference to FIG. FIG. 5 is a schematic diagram illustrating frequency bands and frequency channels used in WLAN, BT, and DCL.

  As shown in FIG. 5, each of the communication methods of WLAN, BT, and DCL uses a frequency band (2.4 GHz band) from 2.4 GHz to 2.5 GHz. In each communication method, a channel obtained by dividing the frequency band into a plurality of parts is set. In order to distinguish channels in each communication method, hereinafter, a channel used in WLAN is called a WLAN channel, a channel used in BT is called a BT channel, and a channel used in DCL is called a DCL channel.

  In WLAN, the frequency band from 2.4 GHz to 2.5 GHz is divided into 14 WLAN channels (wch1 to wch14). Each WLAN channel is set to have a wider frequency band than the transmission data, and the WLAN continuously uses one WLAN channel among the 14 WLAN channels, while maintaining one WLAN channel. Wireless communication is performed by a direct spread method that directly spreads the transmission data. In WLAN, the width of the frequency band of one WLAN channel is 20 MHz.

  On the other hand, in BT, the frequency band from 2.4 GHz to 2.5 GHz is divided into 79 BT channels (bch1 to bch79). Then, wireless communication is performed by a frequency hopping method in which the BT channel to be used is changed (hopped) among 79 BT channels every predetermined cycle (for example, 1/1600 seconds) called a hopping cycle. Is called. In BT, the frequency band width of one BT channel is 1 MHz, which is 1/20 of the frequency bandwidth of the WLAN channel.

  In DCL, the frequency band from 2.4 GHz to 2.5 GHz is divided into 89 DCL channels (dch1 to dch89). In DCL, a frequency at which a DCL channel to be used is hopped among, for example, 45 DCL channels selected in advance among 89 DCL channels every hopping period (for example, 1/100 second) different from BT. Wireless communication is performed by the hopping method. In DCL, the width of the frequency band of one DCL channel is 1 MHz.

Here, under the situation where two or more communication systems as described above are mixed, the same frequency band is used by each communication system, so there is a possibility that radio wave interference occurs between the respective communication systems. On the other hand, in Patent Document 1, on the Bluetooth module 11 side that performs wireless communication by BT, the presence of a carrier (radio wave carrying a signal) of the wireless LAN module 21 is detected, and the presence of the carrier is detected. A technique for preventing the occurrence of radio wave interference by avoiding the channel from being used in the Bluetooth module 11 is described.
JP 2002-198868 A (paragraph "0014" etc.)

  Now, when each wireless communication of WLAN, BT and DCL is to be performed by one device, since these wireless communication use the same 2.4 GHz band, radio interference occurs, and each wireless communication There is a risk that the communication quality will be degraded. In particular, in wireless communication in DCL, voice data must be transmitted and received in real time. Therefore, even if a problem occurs in which radio wave interference occurs and errors are mixed in voice data being communicated or voice data cannot be received. It is difficult to adopt a method to recover it. Accordingly, radio wave interference causes noise, sound interruption, and the like, resulting in a decrease in voice quality.

Moreover, the radio wave interference in DCL also occurs for the following reason. That is, in recent years, WLAN has become widespread. A WLAN has a long communication distance, and therefore, radio waves transmitted from a wireless LAN access point or the like that the WLAN itself cannot grasp may reach a wireless communication device related to its use. In such a case, even if a DCL channel having a frequency band that does not overlap with the WLAN channel used in the device itself is selected, there is a possibility that it overlaps with a WLAN channel transmitted from another wireless LAN access point or the like. As a result, it is assumed that it becomes difficult to secure the number of DCL channels necessary for performing hopping in DCL. Therefore, in order to secure a DCL channel necessary for hopping, it is eventually necessary to use a DCL channel whose frequency band overlaps with the WLAN channel in use.

  The present invention has been made in order to solve the above-described problems, and has the effect of radio wave interference on a wireless communication system related to transmission / reception of data having real-time characteristics while supporting three or more wireless communication systems. An object of the present invention is to provide a wireless communication apparatus capable of suppressing the above-described problem.

  In order to achieve this object, the wireless communication device according to claim 1 uses one of a plurality of first wireless channels provided in a predetermined frequency band, and sets the first wireless channel to be used as the first wireless channel. A first wireless communication means for performing wireless communication of one data serving as voice data transmitted / received via a telephone line network by a first wireless communication method switched at a predetermined cycle, and the first wireless communication means used by the first wireless communication means; Send / receive to / from an external device by using a second wireless communication system that uses one of a plurality of second wireless channels provided in a predetermined frequency band and switches the second wireless channel to be used at a second predetermined period. Second wireless communication means for performing wireless communication of other data to be transmitted, and one wireless channel provided in the predetermined frequency band used by the first wireless communication means Wireless of other data transmitted / received to / from an external device by a third wireless communication system that continuously uses a third wireless channel having a frequency band width greater than that of the second wireless channel. The data transmitted / received between the third wireless communication means for performing communication and the external device is the wireless communication by the second wireless communication method performed by the second wireless communication means and the third wireless communication means performed by the third wireless communication means. When transmission / reception is possible by any of the three wireless communication systems, a first request signal for requesting transmission / reception of the data by wireless communication by the second wireless communication system is sent to the external device. And a first request signal transmitting means for transmitting.

  The telephone line network in claim 1 is a PSTN line, as well as an optical communication network used in an optical telephone, which has been widely used in recent years, a mobile telephone communication network, and other communications referred to by a name including a so-called “telephone”. Including the network to obtain.

  According to a second aspect of the present invention, in the wireless communication device according to the first aspect, the start request signal for requesting the start of wireless communication by the third wireless communication method transmitted from the external device is transmitted to the first communication device. A third wireless communication unit comprising: a reception determination unit configured to determine whether or not the wireless communication unit has received the wireless communication unit; wherein the reception determination unit determines that the start request signal has been received; When the data transmitted / received by the wireless communication according to the scheme can be transmitted / received also by the wireless communication according to the second wireless communication scheme performed by the second wireless communication means, the first request signal transmitting means transmits the first request signal. A signal is transmitted to the external device.

  According to a third aspect of the present invention, in the wireless communication device according to the first or second aspect, the first request signal transmission unit is configured to perform the first request signal by the first wireless communication unit. When wireless communication by the first wireless communication method is being performed, the data is transmitted to the external device.

  A wireless communication device according to a fourth aspect is the wireless communication device according to any one of the first to third aspects, wherein the wireless communication by the first wireless communication method performed by the first wireless communication means is completed. And when the data is transmitted / received to / from the external device by wireless communication according to the second wireless communication method in accordance with the first request signal transmitted by the first request signal transmitting means. Second request signal transmitting means for transmitting to the external device a second request signal for requesting to switch data transmission / reception to wireless communication by the third wireless communication method performed by the third wireless communication means; I have.

  A wireless communication device according to claim 5 is the wireless communication device according to any one of claims 1 to 4, wherein communication quality measuring means for measuring communication quality in wireless communication by the first wireless communication method, and the communication A first request signal for controlling the first request signal transmitting means so that the first request signal is transmitted to the external device when the measured value measured by the quality measuring means is less than a predetermined threshold. Transmission control means.

  According to a sixth aspect of the present invention, in the wireless communication device according to the fifth aspect, the first request signal transmission control unit is configured such that when the measured value is greater than a predetermined threshold, the first request signal is The first request signal transmitting means is not controlled to be transmitted to the external device.

  A wireless communication device according to claim 7 is the wireless communication device according to any one of claims 1 to 4, wherein communication quality measuring means for measuring communication quality in wireless communication by the first wireless communication method, and the communication First request signal transmission that does not control the first request signal transmission means so that the first request signal is transmitted to the external device when the measurement value measured by the quality measurement means is greater than a predetermined threshold value. Control means.

  According to the wireless communication device of claim 1, the data transmitted / received to / from the external device by the first request signal transmitted to the external device by the first request signal transmitting unit is the second wireless communication. In the case where transmission / reception is possible by both wireless communication by the system and wireless communication by the third wireless communication system, the transmission / reception of the data can be performed by wireless communication by the second wireless communication system. Here, since the second wireless communication method is a method of switching the second wireless channel to be used at the second predetermined cycle, similarly to the first wireless communication method, if wireless communication is performed by the second wireless communication, The possibility that radio wave interference occurs between the second radio channel and the first radio channel may cause radio wave interference between the third radio channel and the first radio channel that continuously use a predetermined frequency band. Lower than. And since it becomes possible to eliminate or reduce the frequency band continuously used by the third wireless channel, it is possible to increase the number of first wireless channels that can be used while suppressing radio wave interference. Further, the occurrence of radio wave interference can be suppressed. Therefore, there is an effect that it is possible to obtain a wireless communication apparatus capable of suppressing the influence of radio wave interference on a wireless communication system related to data transmission / reception having real-time characteristics.

  According to the wireless communication apparatus of the second aspect, in addition to the effect achieved by the wireless communication apparatus of the first aspect, the following effect is achieved. That is, even when a start request signal for requesting the start of wireless communication by the third wireless communication method is transmitted from the external device from the external device, the start is requested by the third wireless communication method requested by the start request signal. If data transmitted / received by wireless communication can be transmitted / received also by wireless communication by the second wireless communication method, the data is transmitted / received by the first request signal transmitted to the external device by the first request signal transmitting means. Can be performed by wireless communication using the second wireless communication method. In other words, it is possible to suppress the influence of radio wave interference in the first wireless communication system even in such a case without hindering data transmission / reception with the external device by the third wireless communication system.

  According to the wireless communication device of the third aspect, in addition to the effect produced by the wireless communication device according to the first or second aspect, the following effect is obtained. That is, since the first request signal transmission unit is configured to transmit the first request signal to the external device when wireless communication is performed using the first wireless communication method, the first request signal transmission unit is configured to use the first wireless communication method. When data transmitted / received to / from an external device can be transmitted / received by either the wireless communication using the second wireless communication method or the wireless communication using the third wireless communication method during the wireless communication period. Can transmit and receive the data by wireless communication using the second wireless communication method. Therefore, when radio interference becomes a problem in the first wireless communication method, it is possible to appropriately suppress the influence of radio interference.

  According to the wireless communication device of the fourth aspect, in addition to the effect achieved by the wireless communication device according to any one of the first to third aspects, the following effect is achieved. That is, when the data transmission / reception performed with the external device by the wireless communication according to the second wireless communication method according to the first request signal is completed by the second request transmission means when the wireless communication according to the first wireless communication method ends. Switching to wireless communication by the third wireless communication method can be performed by the second request signal transmitted to the external signal. Therefore, in the situation where the problem of radio wave interference cannot occur, wireless communication with an external device is performed using wireless communication using a third wireless communication method different from the second wireless communication method used based on the request by the first request signal. Data can be sent and received between them.

  Note that the third wireless communication method that continuously uses the third wireless channel can perform wireless communication faster than the second wireless communication method that switches the second wireless channel used in the second predetermined period. In some cases, the data can be transmitted and received at high speed.

  According to the wireless communication device of the fifth aspect, in addition to the effect exhibited by the wireless communication device according to any one of the first to fourth aspects, the following effect is achieved. That is, when the measured value of the communication quality in the wireless communication by the first wireless communication method measured by the communication quality measuring means is less than the predetermined threshold, the first request signal transmitting means transmits the first request signal to the external device. With one request signal, data transmission / reception with an external device can be performed by wireless communication using the second wireless communication method. Therefore, in a situation where reception of wireless communication by the first wireless communication method is poor, the first wireless communication method is affected by radio wave interference due to transmission / reception of data between the wireless communication device and the external device, and the communication is performed. It can suppress that quality falls further.

  According to the wireless communication device of the seventh aspect, in addition to the effect produced by the wireless communication device according to any one of the first to fourth aspects, the following effect is produced. That is, when the measured value of the communication quality in the wireless communication by the first wireless communication method measured by the communication quality measuring unit is larger than the predetermined threshold, the first request signal is transmitted by the first request signal transmitting unit. Therefore, data can be transmitted / received to / from an external device using wireless communication by the third wireless communication method. Therefore, under the situation where the reception state of the wireless communication by the first wireless communication method is good, it is possible to perform the wireless communication that ensures the communication quality without performing the special control.

  In addition, according to the radio | wireless communication apparatus of Claim 6, the effect which the radio | wireless communication apparatus of the said Claim 5 and 7 show | plays can be made compatible.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an access point 51, a PC 61, and a child that perform wireless communication between a multifunction peripheral device (hereinafter referred to as “MFP (Multi Function Peripheral)”) 1 and the MFP 1 according to an embodiment of the present invention. 2 is a block diagram showing an electrical configuration of a wireless communication system including a machine 71. FIG.

  In this wireless communication system, the MFP 1 has a wireless LAN (WLAN) function for transmitting / receiving data to / from the access point 51 by wireless communication 200 by wireless LAN (WLAN), and a PC (Personal) by wireless communication 400 by Bluetooth (BT). A Bluetooth (BT) function for transmitting and receiving data to and from a computer 61, and a wireless communication 500 using a digital cordless telephone (DCL), and a call with a digital cordless handset (hereinafter referred to as "slave") 71 A digital cordless telephone (DCL) function to perform, a general telephone function to make a call with an external telephone (not shown) via the telephone network 100, and a print function to print image data received via these functions It is a multi-functional peripheral device.

  Wireless communication 200 using WLAN, wireless communication 400 using BT, and wireless communication 500 using DCL all use a frequency band of 2.4 GHz band (2.4 GHz to 2.5 GHz) (see FIG. 5). Therefore, if the WLAN function, the BT function, and the DCL function are used at the same time, radio waves may interfere with each other in the channels used in the wireless communication 200, 400, 500, and the communication quality of each wireless communication may be degraded. . In particular, since the DCL function must transmit and receive audio data in real time, it is susceptible to radio wave interference as described above.

  The MFP 1 according to the present embodiment is configured to be able to suppress the influence of radio wave interference on the wireless communication 500 performed at least by the DCL function while supporting the WLAN function, the BT function, and the DCL function.

  Next, the electrical configuration of the MFP 1 will be described. As shown in FIG. 1, the MFP 1 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an operation button 15, a liquid crystal display (hereinafter, “LCD (Liquid Crystal Display)”. ) ”16, wireless LAN communication control circuit (hereinafter referred to as“ WLAN communication control circuit ”) 17, Bluetooth communication control device (hereinafter referred to as“ BT communication control circuit ”) 19, digital cordless communication control circuit ( (Hereinafter referred to as “DCL (Digital Cordless) communication control circuit”) 21, handset 23, voice processing circuit 24, NCU (Network Control Unit) 25, and printer 26. It is.

  The CPU 11, ROM 12, and RAM 13 are connected to each other via a bus line 27. The handset 23 and the NCU 25 are connected to the voice processing circuit 24. Further, the operation button 15, LCD 16, WLAN communication control circuit 17, BT communication control circuit 19, DCL communication control circuit 21, audio processing circuit 24, NCU 25, printer 26, and bus line 27 are connected to each other via the input / output port 28. It is connected.

  The CPU 11 has the MFP 1 in accordance with fixed values and programs stored in the ROM 12 and the RAM 13, or various signals transmitted / received via the WLAN communication control circuit 17, the BT communication control circuit 19, the DCL communication control circuit 21, or the NCU 25. It is an arithmetic unit that controls each function being performed and controls each unit connected to the input / output port 28.

  The ROM 12 is a rewritable nonvolatile memory that stores a control program executed by the MFP 1 and fixed values referred to by the control program. Each program for executing the communication control process shown in the flowchart of FIG. 2, the DCL-WLAN communication control process shown in the flowchart of FIG. 3, and the DCL-BT communication control process shown in the flowchart of FIG. 4 is stored in this ROM 12. Yes. The CPU 11 can suppress the influence of radio wave interference on the wireless communication 500 performed by the DCL function by executing these programs.

  The RAM 13 is a rewritable volatile memory, and is a memory for temporarily storing various data when each operation of the MFP 1 is executed. The RAM 13 is provided with a DCL-RSSI memory 13a, a WLAN-RSSI memory 13b, and a BT-RSSI memory 13c.

  The DCL-RSSI memory 13a is used in a DCL wireless communication 500 measured by a received signal strength measurement circuit (hereinafter referred to as “RSSI (Received Signal Strength Indication) measurement circuit”) 21a provided in the DCL communication control circuit 21. It is a memory that stores received signal strength (hereinafter referred to as “RSSI”) that is the strength of a received signal.

  The RSSI in DCL is measured by the RSSI measurement circuit 21a when the CPU 11 instructs the DCL communication control circuit 21 to measure RSSI at predetermined time intervals. The measurement result is notified from the DCL communication control circuit 21 to the CPU 11, and is stored in the DCL-RSSI memory 13a by the CPU 11.

  The WLAN-RSSI memory 13b is a memory for storing RSSI, which is the strength of a signal received in the wireless communication 200 by WLAN, measured by the RSSI measurement circuit 17a provided in the WLAN communication control circuit 17.

  The RSSI in the WLAN is measured by the RSSI measurement circuit 17a when the CPU 11 instructs the WLAN communication control circuit 17 to measure the RSSI at predetermined time intervals. The measurement result is notified from the WLAN communication control circuit 17 to the CPU 11 and stored in the WLAN-RSSI memory 13b by the CPU 11.

  The BT-RSSI memory 13c is a memory for storing RSSI, which is the strength of a signal received in the wireless communication 400 by BT, measured by the RSSI measurement circuit 19a provided in the BT communication control circuit 19.

  The RSSI in the BT is measured by the RSSI measurement circuit 19a when the CPU 11 instructs the BT communication control circuit 19 to measure the RSSI at predetermined time intervals. The measurement result is notified from the BT communication control circuit 19 to the CPU 11 and is stored in the BT-RSSI memory 13 c by the CPU 11.

  The RSSI in the DCL stored in the DCL-RSSI memory 13a and the RSSI in the WLAN stored in the WLAN-RSSI memory 13b are referred to in a DCL-WLAN communication control process (see FIG. 3) described later. The wireless communication 300 by the WLAN when the wireless communication 500 by the DCL is performed is controlled according to the magnitude relationship of the RSSI.

  Further, the RSSI in the DCL stored in the DCL-RSSI memory 13a and the RSSI in the BT stored in the BT-RSSI memory 13c are referred to in a later-described DCL-BT communication control process (see FIG. 4). The radio communication 400 by the BT when the radio communication 500 by the DCL is performed is controlled according to the magnitude relation of each RSSI.

  The operation button 15 is an input button for setting each function such as a WLAN function, a DCL function, and a BT function and instructing various operations. The LCD 16 is a display device for displaying menus, operation states, and the like according to the operation of the operation buttons 15. When the user operates the operation button 15, information corresponding to the operation is displayed on the LCD 16.

  The WLAN communication control circuit 17 has a WLAN antenna 18 and performs wireless communication 200 with an access point 51 having a WLAN antenna 51a in conformity with IEEE 802.11b / g, which is a WLAN standard. It is a circuit to perform.

  Wireless communication 200 by WLAN divides the 2.4 GHz band into 14 wireless LAN channels (wch1 to wch14) (see FIG. 5), and continues to use one of the wireless LAN channels while using the direct spreading method. Perform wireless communication.

  The MFP 1 controls the WLAN communication control circuit 17 so that the external device (not shown) connected to the LAN 600 to which the access point 51 is connected and the PC 61 that performs wireless communication 300 by the WLAN with the access point 51. A WLAN function for transmitting and receiving digital signals constituting various data is realized.

  The WLAN communication control circuit 17 is provided with an RSSI measurement circuit 17a. The RSSI measurement circuit 17a is a circuit that measures RSSI that is the strength of a signal received in the wireless communication 200 by WLAN. When the WLAN communication control circuit 17 receives an RSSI measurement instruction transmitted from the CPU 11, the RSSI measurement circuit 17a receives the RSSI measurement instruction. The circuit 17a measures RSSI in the wireless communication 200 by WLAN and notifies the CPU 11 of the measurement result via the WLAN communication control circuit 17. Then, as described above, the measurement result is stored in the WLAN-RSSI memory 13b by the CPU 11.

  The BT communication control circuit 19 includes the BT antenna 20 and forms various data while performing wireless communication 400 using the BT with the BT communication control circuit 61b of the PC 61 having the BT antenna 61d. It is a circuit that transmits and receives digital signals. The MFP 1 realizes the BT function by controlling the BT communication control circuit 19.

  The wireless communication 400 using the BT divides the 2.4 GHz band into 79 BT channels (bch1 to bch79) (see FIG. 5), and hops between the 79 BT channels every hopping period (1/1600 seconds). Wireless communication is performed by a frequency hopping method. Note that the wireless communication 400 using the BT has a lower communication speed than the wireless communication 200 using the WLAN that continuously uses one WLAN channel. The reason why the communication speed decreases is that hopping control takes time, the frequency occupation width is different from WLAN, and the amount of data that can be transmitted is small.

  The BT communication control circuit 19 is provided with an RSSI measurement circuit 19a. The RSSI measurement circuit 19a is a circuit that measures RSSI, which is the strength of a signal received in the wireless communication 400 by BT. When the BT communication control circuit 19 receives an RSSI measurement instruction transmitted from the CPU 11, the RSSI measurement circuit 19a The circuit 19 a measures the RSSI in the wireless communication 400 using the BT, and notifies the CPU 11 of the measurement result via the BT communication control circuit 19. As described above, the measurement result is stored in the BT-RSSI memory 13c by the CPU 11.

  The DCL communication control circuit 21 includes a DCL antenna 22 and configures voice data by a call while performing wireless communication 500 with the DCL communication control circuit 71a of the slave unit 71 having the DCL antenna 71b. It is a circuit that transmits and receives digital signals. The MFP 1 realizes the DCL function by controlling the DCL communication control circuit 21.

  The wireless communication 500 by DCL divides the 2.4 GHz band into 89 DCL channels (dch1 to dch89), and among these, for example, 45 (hereinafter, 45 channels will be described as an example) DCL channels for a predetermined period. Wireless communication is performed by a frequency hopping method in which hopping is performed every (hopping cycle: 1/100 second).

  The DCL communication control circuit 21 is provided with an RSSI measurement circuit 21a. This RSSI measurement circuit 21a is a circuit that measures RSSI, which is the strength of a signal received in the wireless communication 500 by DCL. When the DCL communication control circuit 21 receives an RSSI measurement instruction transmitted from the CPU 11, it performs RSSI measurement. The circuit 21a measures the RSSI in the wireless communication 500 using DCL, and notifies the CPU 11 of the measurement result via the DCL communication control circuit 21. As described above, the measurement result is stored in the DCL-RSSI memory 13a by the CPU 11.

  The handset 23 is a device for making a call, and has a microphone and a speaker. The audio processing circuit 24 is a circuit that converts an analog audio signal into a digital signal and a digital signal into an analog audio signal, and converts the digital signal transmitted from the slave unit 71 and received by the DCL communication control circuit 21 into an analog audio signal. Then, the data is output to the handset 23 and the NCU 25. In addition, an analog voice signal output when voice is input to the handset 23 and an analog voice signal received by the NCU 25 from an external telephone (not shown) via the telephone line network 100 are converted into digital signals (voices). Data) and output to the DCL communication control circuit 21. The digital signal (audio data) input to the DCL communication control circuit 21 is transmitted to the slave unit 71 via the wireless communication 500.

  The NCU 25 is connected to the telephone line network 100, and transmits a dial signal to the telephone line network 100 or responds to a call signal from the telephone line network 100 to communicate with an external telephone (not shown). It controls calls. The MFP 1 realizes a general telephone function by controlling the NCU 25.

  The printer 26 performs print processing for printing an image received by wireless communication 200 by WLAN, wireless communication 400 by BT, or the like on a recording sheet in a paper feed cassette (not shown) provided in the printer 26. Yes, the MFP 1 realizes a print function by controlling the printer 26.

  Further, the MFP 1 is configured to be able to receive the image data of the image printed by the printer 26 by both of the wireless communication 200 by WLAN and the wireless communication 400 by BT, and receives the image data of the image to be printed. The wireless communication in which the image data is transmitted and received can be switched between the wireless communication 200 by WLAN and the wireless communication 400 by BT.

  Next, the electrical configuration of the access point 51 will be described. This access point 51 has a WLAN antenna 51a, is configured to enable wireless communication 200 with the WLAN communication control circuit 17 of the MFP 1, and with the WLAN communication control circuit 61a of the PC 61. The wireless communication 300 is configured to be possible. The access point 51 is connected to the LAN 600, and has a known circuit that operates as a relay that connects the LAN 600, the MFP 1, and the PC 61 to each other.

  Next, the electrical configuration of the PC 61 will be described. The PC 61 is a computer having a WLAN function for transmitting / receiving data to / from the access point 51 by wireless communication 300 by WLAN and a BT function for transmitting / receiving data to / from the MFP 1 by wireless communication 400 by BT.

  The PC 61 includes a WLAN communication control circuit 61a, a BT communication control circuit 61b, a WLAN antenna 61c, and a BT antenna 61d. The WLAN communication control circuit 61a is a circuit that transmits and receives digital signals constituting various data while performing wireless communication 300 with the access point 51 using the WLAN antenna 61c. The PC 61 controls the WLAN communication control circuit 61 a and designates the communication destination as the MFP 1, whereby the wireless communication 200 and 300 by the WLAN can be performed with the MFP 1 through the access point 51. As a result, data is transmitted and received between the MFP 1 and the PC 61.

  The BT communication control circuit 61b is a circuit that transmits and receives digital signals constituting various data while performing wireless communication 400 with the BT communication control circuit 19 of the MFP 1 using the BT antenna 61d. The BT communication control circuit 61b performs wireless communication 400 with the MFP 1 by hopping the BT channel in synchronization with the BT communication control circuit 19 of the MFP 1. As described above, the PC 61 is configured to transmit and receive data to and from the MFP 1 using both the WLAN function and the BT function.

  Next, the electrical configuration of the slave unit 71 will be described. Handset 71 is a device for making a call with MFP 1 and an external telephone (not shown) connected via telephone line network 100 via wireless communication 500 performed with MFP 1. is there. The subunit | mobile_unit 71 has the DCL communication control circuit 71a and the antenna 71b for DCL.

  The DCL communication control circuit 71a is a circuit that transmits and receives a digital signal that constitutes the voice of a call while performing wireless communication 500 with the DCL communication control circuit 21 of the MFP 1 that functions as a base unit using the DCL antenna 71b. It is. The DCL communication control circuit 71a performs wireless communication 500 with the MFP 1 by hopping the DCL channel in synchronization with the DCL communication control circuit 21 of the MFP 1.

  Next, a processing flow of communication control processing executed by the MFP 1 will be described with reference to FIG. FIG. 2 is a flowchart showing this communication control process. This process is a process for controlling various wireless communication functions such as a WLAN function, a BT function, and a DCL function. When the MFP 1 is turned on, this process is started by the CPU 11 and is repeatedly executed until the power is turned off. .

  In this communication control process, first, the DCL communication control circuit 21 receives whether or not a signal requesting the start of communication of the wireless communication 500 by DCL is received from the slave unit 71, or the wireless communication by DCL to the slave unit 71. It is determined whether or not a signal for requesting 500 to start communication is transmitted (S1).

  If the DCL communication control circuit 21 receives or transmits a signal requesting the start of communication of the wireless communication 500 by DCL (S1: Yes), the DCL communication control circuit 21 Then, a process for performing the wireless communication 500 using the DCL is executed (S2). Thereby, the wireless communication 500 by DCL is performed between the subunit | mobile_unit 71.

  After the process of S2, whether or not the WLAN communication control circuit 17 has received an RTS (Request to Send) signal requesting the start of wireless communication 200 by the WLAN from the access point 51, or to the access point 51 It is determined whether or not an RTS signal requesting the start of wireless communication 200 by WLAN is transmitted (S3).

  If the WLAN communication control circuit 17 receives or transmits an RTS signal requesting the start of wireless communication 200 by WLAN (S3: Yes), DCL-WLAN communication control processing ( (See FIG. 3) (S4). Thereafter, the process returns to the process of S3, and the processes after S3 are executed again.

  In the DCL-WLAN communication control process in S4, when there is a communication start request for the wireless communication 200 by the WLAN during the period in which the wireless communication 500 by the DCL is performed, the influence of the radio wave interference in the wireless communication 500 by the DCL is affected. Wireless communication 200 by WLAN is controlled so as to be suppressed. Details of the DCL-WLAN communication control processing will be described later with reference to FIG.

  On the other hand, as a result of the process of S3, when it is determined by the WLAN communication control circuit 17 that the RTS signal requesting the start of wireless communication 200 by WLAN is not received or transmitted (S3: No), then Whether or not the BT communication control circuit 19 has received a signal requesting the start of communication of the wireless communication 400 by the BT from the PC 61 or whether a signal requesting the start of communication of the wireless communication 400 by the BT has been transmitted to the PC 61 It is determined whether or not (S5).

  When the BT communication control circuit 19 receives or transmits a signal requesting the start of communication of the wireless communication 400 by the BT (S5: Yes), a DCL-BT communication control process (FIG. 4) is executed (S6). Thereafter, the process returns to the process of S3, and the processes after S3 are executed again.

  In the DCL-BT communication control process of S6, when there is a request for starting communication of the wireless communication 400 by the BT during the period in which the wireless communication 500 by the DCL is performed, the influence of the radio wave interference in the wireless communication 500 by the DCL is affected. Wireless communication 400 by BT is controlled so as to be suppressed. Details of the DCL-BT communication control process will be described later with reference to FIG.

  On the other hand, as a result of the processing of S5, when it is determined by the BT communication control circuit 19 that a signal requesting the start of communication of the wireless communication 400 by the BT has not been received or transmitted (S5: No), then DCL The communication control circuit 21 determines whether or not the wireless communication 500 by DCL is continued (S7).

  If it is determined that the wireless communication 500 by DCL is continued (S7: Yes), the process returns to the process of S3 and the processes after S3 are executed again. When it is determined that the DCL wireless communication 500 is not performed as a result of the processing in S7 (S7: No), it is determined that the DCL wireless communication 500 is completed, and the process returns to the processing in S1. Then, the processing after S1 is executed again.

  On the other hand, if it is determined by the DCL communication control circuit 21 that the signal for requesting the start of communication of the wireless communication 500 by DCL is not received or transmitted as a result of the processing of S1 (S1: No), then Whether or not the WLAN communication control circuit 17 has received an RTS signal for requesting the start of communication of the wireless communication 200 by WLAN from the access point 51, or requests the access point 51 to start communication of the wireless communication 200 by WLAN. It is determined whether an RTS signal to be transmitted has been transmitted (S8).

  If the WLAN communication control circuit 17 receives or transmits an RTS signal requesting the start of communication of the wireless communication 200 by WLAN (S8: Yes), the WLAN communication control circuit 17 Then, processing for performing the wireless communication 200 using the WLAN, such as instructing the wireless communication 200 using the WLAN, is executed (S9). Thereby, when the wireless communication 500 by DCL is not performed with the handset 71, the wireless communication 200 by WLAN is performed with the access point 51.

  After the processing of S9, whether or not the DCL communication control circuit 21 has received a signal requesting the start of communication of the DCL wireless communication 500 from the slave unit 71 or whether the DCL wireless communication 500 of the slave unit 71 is in the DCL state. It is determined whether or not a signal for requesting communication start has been transmitted (S10).

  When the DCL communication control circuit 21 receives or transmits a signal requesting the start of communication of the wireless communication 500 by DCL (S10: Yes), the wireless communication 500 by DCL is performed. After executing the process (S11), the process proceeds to S4, and the DCL-WLAN communication control process (see FIG. 3) is executed.

  Thus, there is a communication start request for the wireless communication 500 by DCL during the period in which the wireless communication 200 by WLAN is being performed, and even when the wireless communication 500 is started, the influence of radio wave interference in the wireless communication 500 by DCL. The wireless communication 200 by the WLAN is controlled so as to be suppressed.

  On the other hand, if it is determined by the DCL communication control circuit 21 that the signal for requesting the start of communication of the wireless communication 500 by DCL has not been received or transmitted as a result of the process of S10 (S10: No), then the WLAN It is determined whether or not data to be transmitted / received by the wireless communication 200 is left (S12). This determination is made by comparing the amount of data to be transmitted / received included in the RTS signal, which is a communication start request signal for wireless communication 200 by WLAN, with the amount of data actually transmitted / received.

  If it is determined that the data to be transmitted / received remains as a result of the process of S12 (S12: Yes), the process returns to the process of S9, and the processes after S9 are executed again. Thereby, the presence or absence of the communication start request signal of the wireless communication 500 by DCL can be determined again by the process of S10, and when the communication start request signal of the wireless communication 500 by DCL is transmitted and received (S10: Yes), Through the process of S11, the DCL-WLAN communication control process which is the process of S4 is executed.

  If it is determined as a result of the processing in S12 that there is no remaining data to be transmitted / received in the wireless communication 200 by WLAN (S12: No), it is determined that the wireless communication 200 by WLAN has been completed, and in S1 Returning to the processing, the processing after S1 is executed again.

  On the other hand, as a result of the process of S8, when it is determined by the WLAN communication control circuit 17 that the RTS signal requesting the start of wireless communication 200 by WLAN is not received or transmitted (S8: No), then, Whether or not the BT communication control circuit 19 has received a signal requesting the start of communication of the wireless communication 400 by the BT from the PC 61 or whether a signal requesting the start of communication of the wireless communication 400 by the BT has been transmitted to the PC 61 It is determined whether or not (S13).

  When the BT communication control circuit 19 receives or transmits a signal requesting the start of communication of the wireless communication 400 by the BT (S13: Yes), the BT communication control circuit 19 Then, processing for performing the wireless communication 400 using the BT, such as instructing the wireless communication 400 using the BT, is executed (S14). Thereby, when the wireless communication 500 by DCL is not performed with the subunit | mobile_unit 71, the wireless communication 400 by BT is performed between PC61.

  After the processing of S14, whether or not the DCL communication control circuit 21 has received a signal for requesting the start of communication of the wireless communication 500 by DCL from the slave unit 71 or whether the wireless communication 500 of the DCL by DCL is sent to the slave unit 71. It is determined whether or not a signal for requesting communication start has been transmitted (S15).

  When the DCL communication control circuit 21 receives or transmits a signal requesting the start of communication of the wireless communication 500 by DCL (S15: Yes), the wireless communication 500 by DCL is performed. After executing the process (S16), the process proceeds to S6, and the DCL-BT communication control process (see FIG. 4) is executed.

  Thereby, during the period when the wireless communication 400 by the BT is performed, there is a request for starting the wireless communication 500 by the DCL, and even when the wireless communication 500 is started, the influence of the radio wave interference in the wireless communication 500 by the DCL. The wireless communication 400 using the BT is controlled so as to be suppressed.

  On the other hand, if it is determined by the DCL communication control circuit 21 that the signal for requesting the start of communication of the wireless communication 500 by DCL has not been received or transmitted as a result of the processing of S15 (S15: No), then BT It is determined whether or not there remains data to be transmitted / received in the wireless communication 400 (S17).

  This determination is performed by comparing the amount of data to be transmitted / received included in the communication start request signal of the wireless communication 400 by BT with the amount of data actually transmitted / received. As will be described later, when data transmission / reception is performed by switching from wireless communication 200 using WLAN to wireless communication 400 using BT, it is included in the RTS signal that is a communication start request signal of wireless communication 200 using WLAN. This is done by comparing the amount of data to be transmitted / received with the amount of data actually transmitted / received.

  If it is determined that the data to be transmitted / received remains as a result of the process of S17 (S17: Yes), the process returns to the process of S14, and the processes after S14 are executed again. Thereby, the presence or absence of the communication start request signal of the wireless communication 500 by DCL can be determined again by the processing of S15, and when the communication start request signal of the wireless communication 500 by DCL is transmitted and received (S15: Yes), Through the process of S16, the DCL-BT communication control process, which is the process of S6, is executed.

  On the other hand, as a result of the processing of S17, when it is determined that there is no data to be transmitted / received by the wireless communication 400 using BT (S17: No), it is determined that the wireless communication 400 using BT has ended, and Returning to the processing, the processing after S1 is executed again.

  As described above, when the communication control process is executed by the MFP 1, according to the communication status of each of the wireless communication 200 using WLAN, the wireless communication 400 using BT, and the wireless communication 500 using DCL, and the generation status of the communication start request signal, Wireless communication 200 using WLAN and wireless communication 400 using BT can be controlled so that the influence of radio wave interference in wireless communication 500 is suppressed.

  Next, a processing flow of DCL-WLAN communication control processing executed by the MFP 1 will be described with reference to FIG. FIG. 3 is a flowchart showing the DCL-WLAN communication control process. This process is performed when there is a communication start request for the wireless communication 200 by the WLAN during the period when the wireless communication 500 by the DCL is performed, or when the wireless communication 200 by the WLAN is performed by the DCL. When the wireless communication 500 is started, the process for controlling the wireless communication 200 by the WLAN is executed in the communication control process as described above (see S4 in FIG. 2).

  In this DCL-WLAN communication control process, first, the RSSI in the DCL stored in the DCL-RSSI memory 13a is compared with the RSSI in the WLAN stored in the WLAN-RSSI memory 13b, and the RSSI in the DCL is compared with the RSSI in the WLAN. Is also larger (S21).

  If it is determined that the RSSI in the DCL is larger than the RSSI in the WLAN (S21: Yes), the WLAN communication control circuit 17 is instructed to perform the wireless communication 200 by the WLAN. Processing for performing 200 is executed (S22). Thereby, when it is possible to perform the wireless communication 500 by DCL in a good reception state, the wireless communication 200 by WLAN is performed simultaneously with the wireless communication 500 by DCL. Therefore, it is possible to perform wireless communication by DCL that ensures call quality without performing special control. Further, as in the case where it is impossible to perform wireless communication 500 using DCL, which will be described later, in a good reception state, wireless communication 200 using WLAN is temporarily stopped or switched to wireless communication 400 using BT. Compared to the case, when the reception state of the wireless communication 500 by DCL is good, data transmission / reception with an external device such as the PC 61 can be performed at high speed.

  After the process of S22, the DCL communication control circuit 21 determines whether or not the wireless communication 500 by DCL is continued (S23). If it is determined that the DCL wireless communication 500 is still being performed (S23: Yes), it is further determined whether or not data to be transmitted / received by the WLAN wireless communication 200 remains (S24). ). This determination compares the amount of data to be transmitted / received included in the RTS signal, which is a communication start request signal for wireless communication 200 by WLAN, with the amount of data actually transmitted / received, as in the process of S12 of the communication control process. Is done.

  If it is determined as a result of the process of S24 that data to be transmitted / received remains (S24: Yes), the process returns to the process of S21, and the processes after S21 are executed again. Thereby, the size comparison between the RSSI in the DCL and the RSSI in the WLAN is performed again by the process of S21, and appropriate control can be performed on the wireless communication 200 by the WLAN according to the size relationship.

  On the other hand, as a result of the process of S24, when it is determined that there is no data to be transmitted / received by the wireless communication 200 by WLAN (S24: No), in the situation where the wireless communication 500 by DCL is continuously performed, It is determined that the wireless communication 200 using the WLAN has ended, and the DCL-WLAN communication control process is ended. As a result, the process returns to the communication control process, and the processes after S3 of the communication control process (see FIG. 2) are executed.

  Also, as a result of the processing of S23, even when it is determined that the wireless communication 500 by DCL is not performed (S23: No), it is determined whether or not data to be transmitted and received by the wireless communication 200 by WLAN remains. (S25).

  If it is determined that there remains data to be transmitted / received as a result of the process of S25 (S25: Yes), the process goes through the DCL-WLAN communication control process and proceeds to the process of S9 of the communication control process. Then (see FIG. 2), the process after S9 of this communication control process is executed. Thereby, the presence or absence of the communication start request signal of the wireless communication 500 by DCL can be determined again by the process of S10, and when the communication start request signal of the wireless communication 500 by DCL is transmitted and received (S10: Yes), After the process of S11, the DCL-WLAN communication control process is executed again.

  On the other hand, as a result of the processing of S25, when it is determined that there is no remaining data to be transmitted / received by the wireless communication 200 by WLAN (S25: No), the wireless communication 500 by DCL and the wireless communication 200 by WLAN are finished. Is determined, and this DCL-WLAN communication control process is exited and the process proceeds to S1 of the communication control process (see FIG. 2). Thereby, the process after S1 is performed again.

  On the other hand, if it is determined that the RSSI in the DCL is equal to or less than the RSSI in the WLAN as a result of the processing in S21 (S21: No), the data transmitted / received by the wireless communication 200 by the WLAN is then transmitted to the PC 61. It is determined whether the data can be transmitted / received also by the wireless communication 400 using BT (S26). For example, if the data transmitted / received to / from the PC 61 by the wireless communication 200 by WLAN is image data of an image printed by the printer 26, the data is determined as data that can also be transmitted / received by the wireless communication 400 by BT. .

  If it is determined as a result of the processing in S26 that data transmitted / received by the wireless communication 200 by WLAN cannot be transmitted / received by the wireless communication 400 by BT (S26: No), the processing in S22 is skipped. At the same time, the process proceeds to S23, and the processes after S23 are executed.

  Thereby, when the wireless communication 500 by DCL cannot be performed in a good reception state, and further, data transmitted / received by the wireless communication 200 by WLAN cannot be transmitted / received by the wireless communication 400 by BT, Wireless communication 200 using WLAN is temporarily suspended. Accordingly, the DCL channel used in the DCL-based wireless communication 500 can be suppressed from being affected by radio wave interference by the WLAN channel continuously used in the WLAN-based wireless communication 200. It is possible to prevent the quality from deteriorating.

  On the other hand, as a result of the processing of S26, when it is determined that the data transmitted / received by the wireless communication 200 by WLAN can be transmitted / received by the wireless communication 400 by BT (S26: Yes), the wireless communication 200 by WLAN starts. The WLAN communication control circuit 17 is instructed to transmit to the PC 61 a switching request signal that requests switching to the wireless communication 400 using BT to perform data transmission / reception (S27). Then, processing for performing the wireless communication 400 using the BT, such as instructing the BT communication control circuit 19 to perform the wireless communication 400 using the BT, is performed (S28).

  Accordingly, when the wireless communication 500 by DCL cannot be performed in a good reception state, and the data transmitted / received by the wireless communication 200 by WLAN can be transmitted / received by the wireless communication 400 by BT as well, Data transmitted and received by the wireless communication 200 can be switched to the wireless communication 400 by BT and transmitted / received.

  Here, the radio communication 500 by DCL is performed by the frequency hopping method, and the radio communication 400 by BT is also performed by the frequency hopping method. That is, since both the DCL channel used in the DCL wireless communication 500 and the BT channel used in the BT wireless communication 400 are switched randomly in each hopping cycle, there is no difference between the DCL channel and the BT channel. The possibility that radio wave interference will occur is lower than the possibility that radio wave interference will occur between the DCL channel and the WLAN channel used in the wireless communication 200 using WLAN.

  Since the frequency band continuously used by the wireless communication 200 by WLAN can be eliminated or reduced, the number of DCL channels that can be used while suppressing radio wave interference can be increased. The occurrence of radio wave interference can be suppressed. Therefore, it is possible to suppress further deterioration in the call quality due to the influence of radio wave interference on the wireless communication 500 using DCL having a poor reception status.

  Next, after the processing of S28, the DCL communication control circuit 21 determines whether or not the wireless communication 500 by DCL is continued (S29). If it is determined that the DCL wireless communication 500 is continuously performed (S29: Yes), it is further determined whether or not data to be transmitted / received by the BT wireless communication 400 remains (S30). ). This determination is based on the amount of data to be transmitted / received in the RTS signal, which is the communication start request signal of the wireless communication 200 by WLAN, transmitted and received by the WLAN communication control circuit 17 before switching to the wireless communication 400 by BT, and the actual transmission / reception. This is done by comparing the amount of data obtained.

  If it is determined that there remains data to be transmitted / received as a result of the process of S30 (S30: Yes), this DCL-WLAN communication control process is exited, and the process proceeds to S6 of the communication control process. , DCL-BT communication control processing is executed. Thereby, when the wireless communication 500 by DCL and the wireless communication 400 by BT are performed simultaneously, the wireless communication 400 by BT is controlled so that the influence of radio wave interference is suppressed in the wireless communication 500 by DCL. The

  On the other hand, as a result of the process of S30, when it is determined that there is no remaining data to be transmitted / received by the wireless communication 400 by BT (S30: No), in the situation where the wireless communication 500 by DCL is continuously performed, It is determined that the wireless communication 400 using the BT has ended, and this DCL-WLAN communication control process is ended. As a result, the process returns to the communication control process, and the processes after S3 of the communication control process (see FIG. 2) are executed.

  Further, when it is determined that the wireless communication 500 by DCL is not performed as a result of the processing of S29 (S29: No), it is determined whether or not data to be transmitted / received by the wireless communication 400 by BT remains. (S31).

  If it is determined as a result of the processing in S31 that data to be transmitted / received remains (S31: Yes), the wireless communication 500 by DCL is completed, so the wireless communication 400 by BT is changed from the wireless communication 400 by WLAN. The WLAN communication control circuit 17 is instructed to switch to the wireless communication 200 and transmit a switching request signal for requesting transmission / reception of the remaining data to the PC 61 (S32).

  Thus, data transmission / reception with the PC 61 that has been switched to the wireless communication 400 using the BT by the process of S27 can be performed by switching to the wireless communication 200 using the WLAN. Further, during the period in which the DCL wireless communication 500 is not performed, the influence of radio wave interference does not become a problem in the wireless communication 500, and data is transmitted to and received from the PC 61 using the wireless communication 200 by WLAN. Therefore, the data can be transmitted and received at high speed.

  When the process of S32 ends, the DCL-WLAN communication control process is exited, the process proceeds to the process of S9 of the communication control process (see FIG. 2), and the processes after S9 of this communication control process are executed. Thereby, the presence or absence of the communication start request signal of the wireless communication 500 by DCL can be determined again by the process of S10, and when the communication start request signal of the wireless communication 500 by DCL is transmitted and received (S10: Yes), After the process of S11, the DCL-WLAN communication control process is executed again.

  On the other hand, as a result of the processing of S31, when it is determined that there is no data to be transmitted / received by the wireless communication 400 using the BT (S31: No), the wireless communication 500 using the DCL is completed and the wireless communication using the BT is performed. Since it can be determined that all data to be transmitted / received in the wireless communication 200 by the WLAN has been transmitted / received by the communication 400, the DCL-WLAN communication control process is skipped and the process proceeds to the process S1 of the communication control process (see FIG. 2). . Thereby, the process after S1 is performed again.

  As described above, this DCL-WLAN communication control process is performed when there is a communication start request for wireless communication 200 by WLAN during a period in which wireless communication 500 by DCL is performed, or when wireless communication 200 by WLAN is performed. When the wireless communication 500 by DCL is started during a certain period, it is executed in the communication control process (see FIG. 2).

  If the data transmitted / received by the wireless communication 200 by the WLAN can be transmitted / received by the wireless communication 400 by the BT, the data transmitted / received by the wireless communication 200 by the WLAN is switched to the wireless communication 400 by the BT and transmitted / received. Is done. Thereby, in the radio communication 500 by DCL during radio communication, when radio wave interference becomes a problem, the influence of radio wave interference can be suppressed by appropriately transmitting and receiving the data.

  In addition, when the DCL-WLAN communication control process transmits the RTS signal requesting the start of communication by the wireless communication 200 from the WLAN communication control device 17, the RTS signal is transmitted from the PC 61 to the WLAN communication control device 17. Even if it is transmitted, if data transmitted / received by wireless communication 200 by WLAN requested to start by the RTS signal can be transmitted / received by wireless communication 400 by BT, wireless communication by BT to PC 61 A switch request signal to 400 is transmitted. Thereby, the transmission / reception of the data can be performed by the wireless communication 400 by BT. In other words, even in such a case, it is possible to suppress the influence of radio wave interference in the DCL wireless communication 200 without hindering data transmission / reception with the PC 61 by the wireless communication 200 using WLAN.

  Next, a processing flow of DCL-BT communication control processing executed by the MFP 1 will be described with reference to FIG. FIG. 4 is a flowchart showing this DCL-BT communication control process. This processing is performed when the wireless communication 400 by the BT is started during the period in which the wireless communication 500 by the DCL is performed, or when the wireless communication 400 by the DCL is performed during the period in which the wireless communication 400 by the BT is performed. Is started in the communication control process as described above in the process of controlling the wireless communication 400 by the BT (see S6 in FIG. 2).

  In this DCL-BT communication control process, first, the RSSI in the DCL stored in the DCL-RSSI memory 13a is compared with the RSSI in the BT stored in the BT-RSSI memory 13c, and the RSSI in the DCL is compared with the RSSI in the BT. Is also determined whether it is larger (S41).

  If it is determined that the RSSI in the DCL is larger than the RSSI in the BT (S41: Yes), the BT wireless communication such as instructing the BT communication control circuit 19 to perform the wireless communication 400 by the BT is performed. Processing for performing 400 is executed (S42). Thereby, when it is possible to perform the wireless communication 500 by DCL in a good reception state, the wireless communication 400 by BT is performed simultaneously with the wireless communication 500 by DCL.

  After the processing of S42, the DCL communication control circuit 21 determines whether or not the DCL wireless communication 500 is continued (S43). If it is determined that the wireless communication 500 using DCL continues (S43: Yes), it is further determined whether or not data to be transmitted and received in the wireless communication 200 using BT remains (S44). ).

  This determination is performed by comparing the data amount to be transmitted / received included in the communication start request signal of the wireless communication 400 by the BT with the actually transmitted / received data amount, as in the process of S17 of the communication control process. . In addition, when the data transmission / reception is performed by switching from the wireless communication 200 by the WLAN to the wireless communication 400 by the BT by the above-described DCL-WLAN communication control process, the communication start request signal of the wireless communication 200 by the WLAN is used. This is done by comparing the amount of data to be transmitted / received included in the RTS signal with the amount of data actually transmitted / received.

  If it is determined as a result of the process of S44 that data to be transmitted / received remains (S44: Yes), the process returns to the process of S41, and the processes after S41 are executed again. Thereby, the size comparison between the RSSI in the DCL and the RSSI in the BT is performed again by the processing of S41, and appropriate control can be performed on the wireless communication 400 by the BT according to the size relationship.

  On the other hand, as a result of the processing of S44, when it is determined that there is no data to be transmitted / received by the wireless communication 400 by BT (S44: No), in the situation where the wireless communication 500 by DCL is continuously performed, It is determined that the wireless communication 400 using the BT has ended, and this DCL-WLAN communication control process is ended. As a result, the process returns to the communication control process, and the processes after S3 of the communication control process (see FIG. 2) are executed.

  Further, when it is determined that the wireless communication 500 by DCL is not performed as a result of the processing of S43 (S43: No), it is determined whether or not data to be transmitted / received by the wireless communication 400 by BT remains. (S45).

  If it is determined that there remains data to be transmitted / received as a result of the process of S45 (S45: Yes), the process exits this DCL-BT communication control process and proceeds to the process of S14 of the communication control process. Then (see FIG. 2), the processing after S14 of this communication control processing is executed. Thereby, the presence or absence of the communication start request signal of the wireless communication 500 by DCL can be determined again by the processing of S15, and when the communication start request signal of the wireless communication 500 by DCL is transmitted and received (S15: Yes), After the process of S16, the DCL-BT communication control process is executed again.

  On the other hand, as a result of the process of S45, when it is determined that there is no data to be transmitted / received by the wireless communication 400 by the BT (S45: No), the wireless communication 500 by the DCL and the wireless communication 400 by the BT are finished. Is determined, the DCL-BT communication control process is exited, and the process proceeds to S1 of the communication control process (see FIG. 2). Thereby, the process after S1 is performed again.

  On the other hand, if it is determined that the RSSI in the DCL is equal to or less than the RSSI in the BT as a result of the process in S41 (S41: No), an interruption instruction signal for instructing to interrupt the wireless communication 400 by the BT is sent to the PC 61. To the BT communication control circuit 19 (S46).

  Thereby, when the wireless communication 500 by DCL cannot be performed in a good reception state, data transmission / reception is not performed by the wireless communication 400 by BT, so the DCL channel used by the wireless communication 500 by DCL, It is possible to completely avoid the occurrence of radio wave interference with the BT channel used by the wireless communication 400 using the BT. Therefore, in the wireless communication 500 using DCL, it is possible to reliably prevent the call quality from deteriorating.

  After the processing of S46, the DCL communication control circuit 21 determines whether or not the DCL wireless communication 500 is continuously performed (S47). If it is determined that the wireless communication 500 by DCL is continued (S47: Yes), the process returns to S41, and the processes after S41 are executed again. Thereby, the size comparison between the RSSI in the DCL and the RSSI in the BT is performed again by the processing of S41, and appropriate control can be performed on the wireless communication 400 by the BT according to the size relationship.

  On the other hand, if it is determined as a result of the processing of S47 that the wireless communication 500 by DCL is not performed (S47: No), a restart instruction signal for instructing to restart the wireless communication 400 by BT is sent to the PC 61. The BT communication control circuit 19 is instructed to transmit (S48). Thereby, during the period when the wireless communication 500 by DCL is not performed, the influence of the radio wave interference does not become a problem in the wireless communication 500, and the wireless communication 400 by the BT is resumed. Can send and receive.

  When the process of S48 is completed, the DCL-BT communication control process is exited, the process proceeds to the process of S14 of the communication control process (see FIG. 2), and the processes after S14 of the communication control process are executed. Thereby, the presence or absence of the communication start request signal of the wireless communication 500 by DCL can be determined again by the processing of S15, and when the communication start request signal of the wireless communication 500 by DCL is transmitted and received (S15: Yes), After the process of S16, the DCL-WLAN communication control process is executed again.

  Thus, when the DCL-BT communication control process is executed by the CPU 11 and the reception status of the wireless communication 500 by DCL is good, the wireless communication 500 by DCL and the wireless communication 400 by BT are simultaneously performed. Even in such a case, the radio communication 500 using DCL is not greatly affected by radio wave interference. Therefore, control is performed such that the wireless communication 500 using DCL and the wireless communication 400 using BT are performed simultaneously. On the other hand, when the reception status of the wireless communication 500 by DCL is bad, the wireless communication 400 by the BT is interrupted until the wireless communication 500 by DCL ends or the reception status of the wireless communication 500 becomes good. Thereby, in the wireless communication 500 by DCL, the influence of the radio wave interference generated between the wireless communication 400 by BT can be surely suppressed, and it is possible to reliably prevent the call quality from deteriorating. As described above, the DCL-BT communication control process can control the radio communication 400 using the BT while suppressing the influence of radio wave interference in the radio communication 500 using the DCL.

  As described above, according to the MFP 1 in the present embodiment, when data transmitted / received to / from an external device such as the PC 61 can be transmitted / received by either the wireless communication 200 using WLAN or the wireless communication 400 using BT, Data can be transmitted and received by wireless communication 400 using BT. As described above, the wireless communication 200 using the WLAN continuously uses one WLAN channel, whereas the wireless communication 400 using the BT and the wireless communication 500 using the DCL are hopped on the BT channel or the DCL channel to be used. Therefore, the possibility of radio wave interference between the radio communication 400 using BT and the radio communication 500 using DCL is lower than the possibility of radio wave interference between the radio communication 200 using the WLAN and the radio communication 500 using DCL. Become. Therefore, it is possible to suppress the influence of radio wave interference on the wireless communication 500 performed at least by the DCL function while supporting the WLAN function, the BT function, and the DCL function.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications and changes can be easily made without departing from the spirit of the present invention. Can be inferred. For example, the numerical values given in the above embodiments are merely examples, and other numerical values can naturally be adopted.

  In the above embodiment, the DCL wireless communication system has been described as an example of the first wireless communication system of the present invention. However, the present invention is not limited to this, and other frequency hopping wireless communication systems may be adopted. Good. For example, a wireless communication system based on Bluetooth may be used. Note that the first wireless communication system of the present invention does not have a data retransmission function, and cannot retransmit the data when an error is mixed in the received data or the data cannot be received due to radio wave interference. If the thing is applied, the effect of this invention can be enjoyed more. Further, even when a wireless communication system that transmits and receives data requiring real-time performance is applied as the first wireless communication system of the present invention, the effects of the present invention can be further enjoyed.

  In the above embodiment, the BT wireless communication method has been described as an example of the second wireless communication method of the present invention. However, the present invention is not limited to this, and other frequency hopping wireless communication methods are employed. May be.

  Furthermore, in the above embodiment, the WLAN wireless communication system has been described as an example of the third wireless communication system of the present invention. However, the present invention is not necessarily limited to this, and the wireless communication system that continuously uses one channel. If so, it is applicable.

  In the above embodiment, in the DCL-WLAN communication control process, the magnitude relationship between RSSI in DCL and RSSI in WLAN is compared. If RSSI in DCL is larger than RSSI in WLAN, reception of wireless communication 500 by DCL is performed. In the case where it is determined that the situation is good and the RSSI in the DCL is equal to or less than the RSSI in the WLAN, it is determined that the reception status of the wireless communication 500 by the DCL is bad and the wireless communication 200 by the WLAN is controlled. However, it is not necessarily limited to this. For example, when a threshold is set according to the RSSI size in the WLAN and the RSSI in the DCL is larger than the threshold, it is determined that the reception status of the wireless communication 500 by the DCL is good, and the RSSI in the DCL is If it is equal to or less than the threshold value, it may be determined that the reception status of the wireless communication 500 by DCL is bad, and the wireless communication 200 by WLAN may be controlled. Further, the threshold value may be a fixed value regardless of the RSSI size in the WLAN, or may be set to an arbitrary value by the user.

  Similarly, in the above embodiment, in the DCL-BT communication control process, the magnitude relationship between RSSI in DCL and RSSI in BT is compared. When RSSI in DCL is larger than RSSI in BT, The case where it is determined that the reception status is good and the RSSI in the DCL is equal to or less than the RSSI in the BT, the reception status of the radio communication 500 by the DCL is determined to be bad, and the radio communication 400 by the BT is controlled is described. However, it is not necessarily limited to this. For example, when a threshold is set according to the RSSI size in the BT and the RSSI in the DCL is larger than the threshold, it is determined that the reception status of the wireless communication 500 by the DCL is good, and the RSSI in the DCL is If it is equal to or less than the threshold, it may be determined that the reception status of the wireless communication 500 by DCL is bad, and the wireless communication 200 by BT may be controlled. The threshold value may be a fixed value regardless of the RSSI size in the BT, or may be set to an arbitrary value by the user.

  Furthermore, in the above embodiment, the case where RSSI in DCL, WLAN, and BT is measured and compared has been described. However, the present invention is not necessarily limited to this, and the bit error rate (BER: Bit) in each of DCL, WLAN, and BT Error Rate) may be measured and compared. In this case, it can be determined that the smaller the BER value, the better the reception state. When measuring the BER, the WLAN communication control circuit 17, the BT communication control circuit 19 and the DCL communication control circuit 21 of the MFP 1 are each provided with a BER measurement circuit, and the access point 51, the PC 61 and the slave unit 71 are respectively provided. A BER measurement radio wave transmission circuit may be provided. Then, BER measurement radio waves are transmitted from the BER measurement radio wave transmission circuits of the access point 51, the PC 61, and the slave unit 7, respectively, and the WLAN communication control circuit 17, the BT communication control circuit 19, and the DCL communication control circuit 21 respectively respond. It is only necessary to measure the BER of the received radio wave in each BER measurement circuit after receiving the radio wave for BER measurement.

1 is a block diagram showing an electrical configuration of a wireless communication system including an MFP according to an embodiment of the present invention. 6 is a flowchart illustrating communication control processing executed by the MFP. 6 is a flowchart showing DCL-WLAN communication control processing executed in the MFP. 6 is a flowchart showing DCL-BT communication control processing executed in the MFP. It is the schematic which showed the frequency band and frequency channel which are used by WLAN, BT, and DCL.

Explanation of symbols

1 MFP (an example of a wireless communication device)
17 WLAN communication control circuit (an example of third wireless communication means)
19 BT communication control circuit (an example of second wireless communication means)
21 DCL communication control circuit (an example of first wireless communication means)
21a RSSI measurement circuit (an example of communication quality measurement means)
61 PC (an example of an external device)
bch1 to bch79 BT channel (example of second radio channel)
dch1 to dch89 DCL channel (example of first radio channel)
wch1-wch14 WLAN channel (example of third wireless channel)
S3, S8 (an example of reception determination means)
S21 (an example of first request signal transmission control means)
S27 (an example of first request signal transmission means)
S32 (an example of second request signal transmission means)

Claims (7)

Using one of the first radio channels provided in a predetermined frequency band, and transmitting and receiving via the telephone line network by the first radio communication system that switches the first radio channel to be used at the first predetermined period. First wireless communication means for performing wireless communication of one piece of data to be audio data;
Second wireless communication using one of a plurality of second wireless channels provided in the predetermined frequency band used by the first wireless communication means and switching the second wireless channel to be used at a second predetermined period A second wireless communication means for performing wireless communication of other data transmitted / received to / from an external device according to a method;
A third wireless channel that is provided in the predetermined frequency band used by the first wireless communication means and whose width of the frequency band of one wireless channel is larger than the width of the frequency band of the second wireless channel is continuously used. A third wireless communication means for performing wireless communication of other data transmitted / received to / from an external device by the third wireless communication method;
Data transmitted / received to / from an external device is either wireless communication using the second wireless communication method performed by the second wireless communication unit or wireless communication using the third wireless communication method performed by the third wireless communication unit. A first request signal transmitting means for transmitting to the external device a first request signal that requests transmission / reception of the data by wireless communication using the second wireless communication method. A wireless communication apparatus comprising: Receiving determination means for determining whether or not the third wireless communication means has received a start request signal for requesting start of wireless communication by the third wireless communication method transmitted from the external device;
Data received and transmitted by wireless communication according to the third wireless communication method that is determined by the reception determining means to have received the start request signal and requested to start by the start request signal is performed by the second wireless communication means. The first request signal transmitting means transmits the first request signal to the external device when transmission / reception is possible even by wireless communication using the second wireless communication method. A wireless communication device according to 1.   The first request signal transmitting unit transmits the first request signal to the external device when wireless communication is performed by the first wireless communication method performed by the first wireless communication unit. The wireless communication device according to claim 1, wherein the wireless communication device is a wireless communication device.   When wireless communication by the first wireless communication method performed by the first wireless communication means is completed, according to the first request signal transmitted by the first request signal transmission means, by the second wireless communication method When the transmission / reception of the data is performed with the external device by wireless communication, the data transmission / reception is switched to the wireless communication by the third wireless communication method performed by the third wireless communication unit. 4. The wireless communication apparatus according to claim 1, further comprising a second request signal transmission unit configured to transmit a second request signal for requesting to the external apparatus. 5. Communication quality measuring means for measuring communication quality in wireless communication by the first wireless communication method;
A first control unit configured to control the first request signal transmission unit so that the first request signal is transmitted to the external device when a measurement value measured by the communication quality measurement unit is less than a predetermined threshold; 5. The wireless communication apparatus according to claim 1, further comprising request signal transmission control means.   The first request signal transmission control means does not control the first request signal transmission means so that the first request signal is transmitted to the external device when the measured value is larger than a predetermined threshold value. The wireless communication apparatus according to claim 5. Communication quality measuring means for measuring communication quality in wireless communication by the first wireless communication method;
A first request that does not control the first request signal transmitting unit so that the first request signal is transmitted to the external device when the measured value measured by the communication quality measuring unit is greater than a predetermined threshold. 5. The wireless communication apparatus according to claim 1, further comprising a signal transmission control unit.

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