JP2009088791A - Radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system capable of executing radio communication of audio data with high sound quality while securing the number of channels required for radio communication even in an environment where there are a lot of channels without excelling in a communication condition. <P>SOLUTION: DCL channels ch1-ch89 used for a communication system by a digital cordless telephone (DCL) are classified into DCL channels that excel in a communication condition and DCL channels that do not excel in the communication condition in accordance with reception electric field intensity of external radio waves measured by a reception electric field intensity measurement circuit 19a. When a sound equal to or more than a predetermined level is included in audio data used for executing communication by a communication system by a DCL, communication is executed by using the DCL channel that excels in the communication condition, otherwise communication is executed by using the DCL channel without excelling in the communication condition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless communication system.

  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 (Local Area Network) for data communication and a digital cordless telephone (hereinafter referred to as “DCL (Digital Cordless)”) for the purpose of calling are both the same 2.4 GHz band. Use the frequency band.

  Here, frequency bands and frequency channels used in the wireless LAN and DCL will be described with reference to FIG. FIG. 6 is a schematic diagram showing frequency bands and frequency channels used in wireless LAN and DCL.

  As shown in FIG. 6, each of the wireless LAN and DCL communication systems 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 the wireless LAN is referred to as a wireless LAN channel, and a channel used in the DCL is referred to as a DCL channel.

  In the wireless LAN, the frequency band from 2.4 GHz to 2.5 GHz is divided into 14 wireless LAN channels (wch1 to wch14). In the wireless LAN, one of the 14 wireless LAN channels is continuously used.

  On the other hand, in DCL, the frequency band from 2.4 GHz to 2.5 GHz is divided into 89 channels (ch1 to ch89). Then, the DCL channel to be used is changed (hopped) every predetermined cycle (for example, about 1/100 second) called a hopping cycle. In DCL, in order to perform this hopping, it is necessary to secure, for example, 45 channels of DCL channels.

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, Patent Document 1 detects the presence of a carrier (radio wave carrying a signal) of the wireless LAN module 21 on the Bluetooth module 11 side that performs wireless communication using Bluetooth, which is one of communication methods, and detects the carrier. A technique for preventing radio interference from occurring by stopping the use of the wireless channel in which the presence of the Bluetooth module 11 is used in the Bluetooth module 11 is described.
JP 2002-198868 A (paragraph "0014" etc.)

  Now, when radio interference occurs when performing wireless communication in DCL, problems such as errors being mixed in the voice data being communicated and the voice data being unable to be received occur, which causes noise and sound interruptions. Voice quality is reduced. Therefore, the technique described in Patent Document 1 described above is applied to DCL, the presence of a carrier in another wireless communication system is detected on the DCL side, and the DCL channel in which the presence of the carrier is detected is used by DCL. It is conceivable to prevent the occurrence of radio wave interference by stopping the transmission.

  However, with this method, the number of DCL channels that can be used by DCL is limited, and in an environment where the presence of many carriers is detected, the number of DCL channels necessary for hopping by DCL is ensured. There was a problem that it was impossible to do.

  The present invention has been made to solve the above-described problems. Even in an environment where there are many channels with poor communication conditions, the present invention is based on wireless communication while securing the number of channels necessary for wireless communication. An object of the present invention is to provide a wireless communication system capable of performing voice data communication with high sound quality.

  In order to achieve this object, the wireless communication system according to claim 1 is wirelessly using at least one first wireless channel among a plurality of first wireless channels provided in a predetermined frequency band. In a wireless communication system including first wireless communication means for performing communication of audio data, whether or not the communication state is good for each first wireless channel with respect to some or all of the plurality of first wireless channels. Communication status determining means for determining, first storage means for storing the first radio channel determined to be good by the communication status determining means, and communication status determining means determining that the communication status is not good The second storage means for storing the first wireless channel and the size of the sound included in the sound data communicated by the first wireless communication means is a first threshold value. When the voice detection means for detecting whether or not the voice is contained in the voice data is detected by the voice detection means, it is stored in the first storage means. At least one of the stored first wireless channels is set as a use channel to be used by the first wireless communication means, and the sound size included in the sound data by the sound detection means is less than the first threshold value. And setting means for setting at least one of the first radio channels stored in the second storage means as the use channel when it is detected.

  According to a second aspect of the present invention, there is provided a radio communication system according to the first aspect, wherein the radio communication system according to the first aspect detects an external radio wave for each of the plurality of first radio channels for each first radio channel. Detecting means and electric field strength measuring means for measuring the electric field strength of the external radio wave detected by the external radio wave detecting means for each of the first wireless channels, and the communication status determining means is measured by the electric field strength measuring means. It is determined that the communication status is good for the first wireless channel whose electric field strength is less than a second threshold value, and the first channel whose electric field strength measured by the electric field strength measuring means is greater than or equal to a second threshold value. On the other hand, it is determined that the communication status is not good.

  A radio communication system according to claim 3 is the radio communication system according to claim 1, wherein a second radio channel whose frequency band overlaps with a part of the predetermined frequency band used by the first radio communication means. A second wireless communication unit that performs wireless communication using the first wireless channel and a frequency band of the second wireless channel used by the second wireless communication unit among the plurality of first wireless channels used by the first wireless communication unit Specifying means for specifying the first radio channel having a frequency band overlapping with the second radio channel, and the communication status determining means is specified by the specifying means as having a frequency band overlapping with the frequency band of the second radio channel. In addition, it is determined that the communication status is not good for the first wireless channel.

  A wireless communication system according to a fourth aspect of the invention is the wireless communication system according to any one of the first to third aspects, further comprising voice detection threshold value changing means for changing the first threshold value in the voice detection means.

  The radio communication system according to claim 5 is the radio communication system according to any one of claims 1 to 4, wherein the first radio communication means changes a first radio channel used at a predetermined period, and The voice detection means detects whether or not the volume of the voice included in the voice data communicated by the first wireless communication means in the next predetermined cycle is greater than or equal to a first threshold, and the setting means When it is detected by the voice detection means that the volume of the voice included in the voice data communicated by the first wireless communication means at the next predetermined cycle is equal to or greater than the first threshold, One of the first wireless channels stored in the first storage means is set as a use channel to be used by the first wireless communication means and communicated by the first wireless communication means at the next predetermined cycle. When it is detected that the volume of the voice included in the voice data to be performed is less than the first threshold value, one of the first wireless channels stored in the second storage means is used in the next cycle. Set as a channel.

  A wireless communication system according to a sixth aspect is the wireless communication system according to any one of the first to fifth aspects, comprising: a parent device connected to an external device via a telephone line; and a microphone; And a handset that performs voice data communication by the first wireless communication means, wherein the voice detection means has a voice level included in the voice data input from the external device equal to or greater than the first threshold value. And whether or not the volume of the voice included in the voice data input from the microphone of the slave unit is greater than or equal to the first threshold value, and the setting means includes the voice detection means Thus, any one of the volume of the voice included in the voice data input from the external device and the volume of the voice included in the voice data input to the microphone of the slave unit is the first When it is detected that the value is greater than or equal to the value, one of the first wireless channels stored in the first storage means is set as a use channel used by the first wireless communication means, and is input from the external device. When it is detected that both the volume of the voice included in the voice data and the volume of the voice included in the voice data input to the microphone of the slave unit are less than the first threshold, (2) One of the first wireless channels stored in the storage means is set as the use channel.

  According to the wireless communication system of the first aspect, the communication status determination unit determines whether or not the communication status is good for each first radio channel. Then, the first wireless channel determined to have a good communication status is stored in the first storage means, and the first wireless channel determined to have a poor communication status is stored in the second storage means. As a result, it is possible to classify the first radio channel having a good communication status and the first radio channel having a poor communication status. When the voice detection means detects that the volume of the voice included in the voice data is greater than or equal to the first threshold, it is determined that the first wireless channel stored in the first storage means, that is, the communication status is good. At least one of the first radio channels thus set is set by the setting unit as a use channel used by the first radio communication unit. On the other hand, when the voice detection means detects that the volume of the voice included in the voice data is less than the first threshold, it is determined that the first wireless channel stored in the second storage means, that is, the communication status is not good. Further, at least one of the first wireless channels is set by the setting means as a use channel used by the first wireless communication means. As described above, since the voice data including the voice having a high level is wirelessly communicated through the first wireless channel in which the communication status is good, the voice data can be transmitted and received without noise and sound interruption. On the other hand, since audio data including only low-level audio or not including audio is wirelessly communicated via the first wireless channel whose communication status is not good, communication status of audio data that does not require sound quality is reduced. It is possible to prevent a good first wireless channel from being assigned unnecessarily. Thereby, even when there are many first wireless channels with poor communication conditions, it is necessary to perform wireless communication by the first wireless communication means including the first wireless channels with poor communication conditions. There is an effect that wireless voice data communication can be performed with high sound quality while securing the first number of radio channels.

  According to the wireless communication system of the second aspect, in addition to the effect achieved by the wireless communication system of the first aspect, the following effect can be obtained. For each first wireless channel, the electric field strength of the external radio wave detected by the external radio wave detection unit is measured by the electric field strength measurement unit. Then, the first wireless channel whose electric field strength measured by the electric field strength measuring means is less than the second threshold is judged to be good in communication status by the communication status judging means, and the electric field strength is equal to or higher than the second threshold. For one wireless channel, the communication status determining means determines that the communication status is not good. If the electric field intensity of the external radio wave is small, good communication can be performed without receiving interference from the external radio wave. On the other hand, if the electric field strength of the external radio wave is large, interference from the external radio wave is received, so that good communication cannot be performed. In the present wireless communication system, as described above, whether or not the communication status for each first wireless channel is good is determined according to the magnitude of the electric field strength of the external radio wave. There is an effect that can be done.

  According to the wireless communication system of the third aspect, in addition to the effect produced by the wireless communication system according to the first aspect, the following effect can be obtained. Used by the second radio communication unit when the second radio communication unit performs radio communication using the second radio channel whose frequency band overlaps with a part of the frequency band used by the first radio communication unit. The first wireless channel that overlaps the frequency band of the second wireless channel is identified by the identifying unit, and the identified first wireless channel is determined by the communication status determining unit if the communication status is not good. As a result, the first wireless channel overlapping the frequency band of the second wireless channel used in the second wireless communication means provided in the wireless communication system does not need to detect the external radio wave and measure the electric field strength. Since it can be determined that the communication status is not good, there is an effect that it is possible to suppress the load required for determining the communication status.

  According to the wireless communication system of the fourth aspect, in addition to the effect achieved by the wireless communication system according to any one of the first to third aspects, the following effect is achieved. The value of the first threshold value in the voice detection means can be changed by the voice detection threshold value changing means. This changes the reference level of the voice in the voice detection means, so the voice data communicated using the first radio channel with good communication status and the first radio channel with poor communication status are used. It is possible to change the criteria for discrimination from the voice data communicated. Therefore, there is an effect that the sound quality of the sound obtained from the sound data communicated by the first wireless communication unit can be adjusted.

  According to the wireless communication system of the fifth aspect, in addition to the effect exhibited by the wireless communication system according to any one of the first to fourth aspects, the following effect is achieved. Whether or not the volume of audio included in audio data to be communicated in the next predetermined cycle is equal to or greater than the first threshold when the first wireless communication unit changes the first wireless channel used in the predetermined cycle. Is previously detected by the voice detection means. If the volume of the audio included in the audio data is equal to or greater than the first threshold, it is determined that the first wireless channel stored in the first storage means, that is, the communication status is good in the predetermined cycle. At least one of the first radio channels thus set is set by the setting unit as a use channel used by the first radio communication unit. On the other hand, if the volume of the audio included in the audio data to be communicated in the next predetermined cycle is less than the first threshold, the first wireless channel stored in the second storage means in the predetermined cycle, that is, At least one of the first radio channels determined to have a poor communication status is set by the setting unit as a use channel used by the first radio communication unit. In this way, the level of the audio level included in the audio data is detected at predetermined intervals, and the first radio channel with good communication status and the first radio channel with poor communication status are detected according to the detection result. From either one of these, the channel used for wirelessly communicating the audio data is set, so that the first wireless channel and the communication with good communication conditions can be adapted to the audio level that changes every moment. An appropriate channel can be set as a use channel from the first wireless channel in which the situation is not good. Accordingly, there is an effect that the first wireless channel secured for performing wireless communication by the first wireless communication unit including the first wireless channel having a poor communication state can be used efficiently.

  In addition, since the voice detection means detects in advance whether or not the volume of the voice included in the voice data to be communicated in the next predetermined cycle is equal to or greater than the first threshold, the predetermined cycle is short. However, according to the detection result, the used channel used in a predetermined cycle can be set without delay from either the first radio channel with a good communication status or the first radio channel with a poor communication status. There is an effect that can be done.

  According to the wireless communication system of the sixth aspect, in addition to the effect achieved by the wireless communication system according to any one of the first to fifth aspects, the following effect is achieved. When voice data is communicated by the first wireless communication means between the master unit connected to the external device via a telephone line and the slave unit equipped with the microphone, the voice input from the external device by the voice detection unit It is detected whether or not the volume of the voice included in the data is greater than or equal to the first threshold value, and whether or not the volume of the voice included in the voice data input from the microphone of the slave unit is greater than or equal to the first threshold value Whether or not is detected. If either one of the volume of the voice included in the voice data input from the external device and the volume of the voice included in the voice data input from the microphone of the slave unit is equal to or greater than the first threshold value, the first storage unit At least one of the first radio channels stored in the first radio channel, that is, the first radio channel determined to have good communication status, is set by the setting means as a use channel used by the first radio communication means. On the other hand, if both the volume of the voice included in the voice data input from the external device and the volume of the voice included in the voice data input from the microphone of the slave unit are less than the first threshold, the second memory is stored. The first wireless channel stored in the means, that is, at least one of the first wireless channels determined to have poor communication status is set by the setting means as a use channel used in the first wireless communication means. In this way, based on the volume of audio included in both audio data input from the external device and audio data input from the handset microphone, the first wireless channel with good communication status is used, It is set whether to use the first wireless channel whose communication status is not good. Accordingly, the first wireless communication including the first wireless channel in which the communication status is not good even when voice data is bidirectionally communicated between the parent device and the child device by the first wireless communication means. There is an effect that wireless voice data communication can be performed with high sound quality between the parent device and the child device while securing the number of first wireless channels necessary for wireless communication by means.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing an electrical configuration of a wireless communication system T according to an embodiment of the present invention. The wireless communication system T includes a multifunction peripheral device (hereinafter referred to as “MFP (Multi Function Peripheral)”) 1, a slave unit 31, and an access point 51.

  The wireless communication system T has a digital cordless telephone (DCL) function for making a call via the wireless communication 200 between the MFP 1 functioning as a parent device and the child device 31, and between the MFP 1 and the access point 51. And a wireless LAN function for connecting to a LAN (Local Area Network) 400 via the wireless communication 300.

  Both the wireless communication 200 using DCL and the wireless communication 300 using wireless LAN perform wireless communication using a frequency band of 2.4 GHz band (2.4 GHz to 2.5 GHz) (see FIG. 6). The DCL wireless communication 200 divides the 2.4 GHz band into 89 DCL channels (ch1 to ch89), and among these 45 DCL channels, every predetermined cycle (hopping cycle: 1/100 second). Wireless communication is performed by a frequency hopping method in which hopping is performed. On the other hand, the wireless communication 300 by the wireless LAN divides the 2.4 GHz band into 14 wireless LAN channels (wch1 to wch14), and performs wireless communication by a direct spreading method using one of the wireless LAN channels.

  In the wireless communication system T, the number of wireless channels (DCL channels) necessary for the wireless communication 300 is ensured even in an environment where there are many wireless channels (DCL channels) with poor communication conditions in the DCL function. On the other hand, the communication of voice data by DCL can be performed with high sound quality.

  Next, a detailed configuration of the MFP 1 will be described. The MFP 1 is a multifunction peripheral device having various functions such as a DCL function and a wireless LAN function. The MFP 1 also has a general telephone function for making a call with the external telephone 2 via the telephone line network 100.

  As shown in FIG. 1, the MFP 1 includes a CPU (Central Processing Unit) 11, an EEPROM (Electronically Erasable and Programmable Read Only Memory) 12, a RAM (Random Access Memory) display 16, a sound determination circuit 14, a sound determination circuit 14, a sound determination circuit 14. (Hereinafter referred to as “LCD (Liquid Crystal Display) 16”), wireless LAN communication control circuit 17, digital cordless communication control circuit 19 (hereinafter referred to as “DCL (Digital Cordless) communication control circuit 19”), transmission A receiver 23, a voice processing circuit 24, and an NCU (Network Control Unit) 25 are provided.

  The CPU 11, EEPROM 12, and RAM 13 are connected to each other via a bus line 26. The handset 23 and the NCU 25 are connected to the voice processing circuit 24. Further, the voice determination circuit 14, the operation button 15, the LCD 16, the wireless LAN communication control circuit 17, the DCL communication control circuit 19, the voice processing circuit 24, the NCU 25, and the bus line 26 are connected to each other via the input / output port 27. Yes.

  The CPU 11 controls each function of the MFP 1 according to fixed values and programs stored in the EEPROM 12 and the RAM 13 or various signals transmitted and received via the wireless LAN communication control circuit 17, the DCL communication control circuit 19 or the NCU 25. And an arithmetic unit that controls each unit connected to the input / output port 27.

  The EEPROM 12 is a rewritable nonvolatile memory that stores a control program executed by the MFP 1. Each program for executing the hopping table generation process (hereinafter referred to as “HP (Hopping) table generation process”) shown in the flowchart of FIG. 4 and the DCL communication process shown in the flowchart of FIG. Stored in The EEPROM 12 includes a wireless LAN channel-DCL channel correspondence memory 12a (hereinafter simply referred to as “channel correspondence memory 12a”), a first DCL channel memory 12b, a second DCL channel memory 12c, a wireless LAN channel memory 12d, and a threshold memory. 12e is provided.

  The channel correspondence memory 12a is a memory for storing a wireless LAN channel-DCL channel correspondence table (hereinafter simply referred to as “channel correspondence table”). Here, the channel correspondence table will be described with reference to FIG. FIG. 2 is a schematic diagram schematically showing the contents of the channel correspondence table.

  The channel correspondence table shows the DCL channel 12a2 whose frequency band overlaps with the corresponding wireless LAN channel for the wireless LAN channel 12a1. The wireless LAN channel 12a1 is divided into 14 wireless LAN channels (wch1 to wch14) provided in the 2.4 GHz band.

  In the DCL channel 12a2, all DCL channels whose frequency bands overlap with the corresponding wireless LAN channel are associated with the wireless LAN channel 12a1. For example, the DCL channel “ch1, ch2,..., Ch25” is associated with the wireless LAN channel “wch1”, and the DCL channel “ch6, ch7,..., Ch30” is associated with the wireless LAN channel “wch2”. It is associated. The wireless LAN channel “wch14” is associated with the DCL channels “ch65, ch66,..., Ch89”.

  This channel correspondence table is referred to in an HP table generation process (see FIG. 4) described later. When the CPU 11 executes the HP table generation processing, when the wireless communication 300 by the wireless LAN is performed in the MFP 1, the CPU 11 refers to the channel correspondence table stored in the channel correspondence memory 12a and is used in the wireless communication 300 by the wireless LAN. The DCL channel corresponding to the wireless LAN channel being used is specified. Since the DCL channel specified here is a channel used by the wireless communication 300 by the wireless LAN, the specified DCL channel is determined as a channel whose communication status is not good.

  Returning to FIG. 1, the description will be continued. The first DCL channel memory 12b is a memory for storing a hopping table (hereinafter referred to as a “good channel HP table”) generated by a plurality of DCL channels determined to have good communication conditions. The second DCL channel memory 12c is a memory for storing a hopping table (hereinafter, referred to as “no good channel HP table”) generated by a plurality of DCL channels determined to have poor communication conditions.

  The hopping table (hereinafter referred to as “HP table”) is a table that defines the order of hopping of DCL channels used in the DCL wireless communication 200. In the present embodiment, when the wireless communication 200 is performed between the MFP 1 and the child device 31 using audio data including high-level audio, the communication status is good according to the order determined by the good channel HP table. Hopping is performed using the determined DCL channel. Further, when the wireless communication 200 is performed between the MFP 1 and the slave unit 31 using audio data including only low-level audio or not including audio, the communication status is determined according to the order determined by the bad channel HP table. Hopping is performed using a DCL channel determined to be not good.

  Here, the contents of the good channel HP table and the bad channel will be described with reference to FIGS. FIG. 3A is a schematic diagram schematically showing an example of the contents of the good channel HP table stored in the first DCL channel memory 12b, and FIG. 3B is a table stored in the second DCL channel memory 12c. It is the schematic diagram which showed typically an example of the content of the failure favorable channel HP table.

  First, as shown in FIG. 3A, the good channel HP table is referred to as a hopping channel 12b2 (hereinafter referred to as “HP channel 12b2”) with respect to a hopping order 12b1 (hereinafter referred to as “HP order 12b1”). .) Are associated with each other. Then, DCL channels (ch1 to ch20 in the example of FIG. 3A) that are determined to have good communication conditions are randomly assigned to the HP channel 12b2.

  The HP order 12b1 indicates the order of DCL channels on which hopping is performed, and is divided by numerical values representing the order. That is, numerical values up to the number of DCL channels whose communication status is determined to be good (“20” in the example of FIG. 3A) are assigned to the HP order 12b2 in order from “1”.

  The HPL 12b2 is associated with the HPL order 12b1 of the DCL channel determined to have a good communication status. That is, in the example shown in FIG. 3A, the HP channel 12b2 “ch1” is associated with the HP order 12b1 “1”, and the HP channel 12b2 “ch3” is associated with the HP order 12b1 “2”. The HP channel 12b2 “ch4” is associated with the HP order 12b1 “3”. The HP channel 12b2 “ch20” is associated with the HP order 12b1 “20”.

  While executing the DCL communication process (see FIG. 5A) described later, the CPU 11 performs a wireless communication 200 of audio data including high-level audio between the MFP 1 and the slave unit 31 in the next hopping cycle. If it is determined, the HP channel 12b2 in the HP order 12b1 indicated by the first DCL channel counter 13b described later is selected from the good channel HP table as the DCL channel to be used in the hopping cycle. Here, each time the first DCL channel counter 13b accesses the good channel HP table (first DCL channel memory 12b) and selects the HP channel 12b2, the first DCL channel counter 13b is incremented by one, and the value indicates that the communication status is good. If the determined number of DCL channels has been reached (“20” in the example of FIG. 3A), “1” is set. As a result, when the wireless communication 200 of audio data including high-level audio is performed between the MFP 1 and the child device 31, “ch1” → “ch3” according to the good channel HP table of FIG. → “ch4” →... → “ch20” → “ch1” → “ch3” →.

  Further, as shown in FIG. 3B, the bad channel HP table is hopping channel 12c2 (hereinafter referred to as “HP channel 12c2”) with respect to hopping order 12c1 (hereinafter referred to as “HP order 12c1”). Are associated with each other. Then, DCL channels (ch21 to ch45 in the example of FIG. 3B) that are determined to have poor communication conditions are randomly assigned to the HP channel 12c2.

  Similarly to the HP order 12b1, the HP order 12c1 is divided into numerical values representing the order of DCL channels on which hopping is performed. That is, numerical values up to the number of DCL channels determined to have poor communication status (“25” in the example of FIG. 3B) are assigned to the HP order 12c2 in order from “1”.

  The HPL 12c2 is associated with the HPL order 12c1 of the DCL channel determined to have a poor communication status. In other words, in the example shown in FIG. 3B, the HP channel 12c2 “ch21” is associated with the HP order 12c1 “1”, and the HP channel 12c2 “ch24” is associated with the HP order 12c1 “2”. The HP channel 12c2 “ch25” is associated with the HP order 12c1 “3”. The HP channel 12c2 “ch40” is associated with the HP order 12c1 “25”.

  While executing the DCL communication process (see FIG. 5A), the CPU 11 wirelessly transmits audio data that includes only low-level audio or no audio between the MFP 1 and the slave unit 31 in the next hopping cycle. When it is determined that the communication 200 is performed, the HP channel 12c2 of the HP order 12c1 indicated by the second DCL channel counter 13c described later is selected from the bad channel HP table as the DCL channel used in the hopping cycle. Here, the second DCL channel counter 13c is incremented by 1 every time the poor channel HP table (second DCL channel memory 12b) is accessed and the HP channel 12c2 is selected. If the determined number of DCL channels has been reached (“25” in the example of FIG. 3B), “1” is set. Thereby, when the wireless communication 200 of audio data including only low-level audio or not including audio is performed between the MFP 1 and the slave unit 31, according to the bad channel HP table of FIG. Hopping is performed in the order of “ch21” → “ch24” → “ch25” →... → “ch40” → “ch21” → “ch24” →.

  As described above, the CPU 11 performs good according to the level of audio included in the audio data for performing the wireless communication 200 between the MFP 1 and the slave unit 31 during the execution of the DCL communication process (see FIG. 5A). The DCL channel to be used is determined for each hopping period in the order shown in each HP table with reference to any one of the poor channel HP tables. The DCL channel determined here is notified to a DCL communication control circuit 19 described later, and the DCL communication control circuit 19 performs DCL wireless communication 200 with the slave unit 31 using the DCL channel. be able to.

  Here, the voice level constantly changes, and the level of the voice level included in the voice data (including no voice) frequently changes every hopping cycle. In the DCL communication processing executed by the CPU 11, the level of the audio level included in the audio data (including no audio) is determined for each hopping cycle, and the DCL channel used in the wireless communication 200 is determined for each hopping cycle. The good and bad channel HP tables used for the determination are selected.

  Further, when the good channel HP table is selected in one hopping cycle, only the first DCL channel counter 13b is updated, and the second DCL channel counter 13c is not updated. As a result, when the bad channel HP table is selected in another hopping cycle, the HP channel 12c2 is selected from the continuation of the HP order 12c1 selected from the previous bad channel HP table. In addition, when the poor channel HP table is selected in one hopping cycle, only the second DCL channel counter 13c is updated, and the first DCL channel counter 13b is not updated. Thereby, when the good channel HP table is selected in another hopping cycle, the HP channel 12b2 is selected from the continuation of the HP order 12b1 selected from the previous good channel HP table.

  The good and bad channel HP tables are generated and updated by the CPU 11 by executing a later-described HP table generation process (see FIG. 4) at a predetermined interval (in this embodiment, every 10 minutes). The The updated good and bad channel HP tables are read from the first and second DCL channel memories 12b and 12c, respectively, and transmitted to the slave unit 31 via the wireless communication 200.

  Returning to FIG. 1, the description will be continued. The wireless LAN channel memory 12d is a memory for storing channel numbers (wch1 to wch14) of wireless LAN channels to be used when performing wireless communication 300 using a wireless LAN. The wireless LAN communication control circuit 17 described later can perform wireless communication 300 using the wireless LAN with the access point 51 using the wireless LAN channel stored in the wireless LAN channel memory 12d.

  The contents of the wireless LAN channel memory 12d can be set by operating the operation buttons 15. When the wireless LAN channel to be used is instructed from the access point 51 to the wireless LAN communication control circuit 17, the wireless LAN channel memory 12d is instructed by the wireless LAN communication control circuit 17 to indicate the wireless LAN channel. To be rewritten.

  The wireless LAN channel memory 12d is referred to during execution of an HP table generation process (see FIG. 4) described later in the CPU 11. As described above, the CPU 11 determines the wireless LAN channel and frequency band used in the wireless communication 300 by the wireless LAN based on the contents of the wireless LAN channel memory 12d and the channel correspondence table stored in the channel correspondence memory 12a. The overlapping DCL channels are identified.

  The threshold value memory 12e is a memory that stores a first threshold value that is referred to in a voice determination circuit 14 that will be described later and a second threshold value that is referred to during execution of a later-described HP table generation process (see FIG. 4) in the CPU 11. .

  The first threshold value is used by the voice determination circuit 14 to determine whether or not the voice data includes a voice of a predetermined level or higher. Based on the content of the first threshold value stored in the threshold value memory 12e, the sound determination circuit 14 has a sound level greater than or equal to a predetermined level when the sound level included in the sound data is greater than or equal to the first threshold value. If the sound level included in the sound data is less than the first threshold, it is determined that the sound data includes only sound of a magnitude less than the predetermined level or does not include sound. To do.

  The second threshold is used in the HP table generation process executed by the CPU 11 to determine whether or not the communication statuses of the plurality of DCL channels are good. When the received electric field strength of the external radio wave measured by the received electric field strength measuring circuit 19a is less than the second threshold value in one DCL channel (determination channel), the CPU 11 is not affected by the external radio wave, so that DCL The channel (determination channel) is determined to have good communication status. If the received electric field intensity of the external radio wave is equal to or higher than the second threshold, it is judged that the DCL channel (determination channel) is not in a good communication state because it receives interference from the external radio wave.

  The first threshold value and the second threshold value are preliminarily stored in the threshold memory 12e in the design stage. However, the first threshold value can be changed by an operation using the operation button 15. Further, when the first threshold is changed, the changed value is notified to the handset 31 via the wireless communication 200.

  By changing the first threshold, it is possible to change the reference for sound determination in the sound determination circuit 14 to be described later. For example, by reducing the first threshold, the sound determined to be equal to or higher than a predetermined level. The level can be expanded.

  When the audio level determined to be equal to or higher than the predetermined level is expanded, the audio data wirelessly communicated using the DCL channel determined to have a good communication state increases. Thereby, the sound quality of a telephone call can be improved. As described above, by changing the first threshold value stored in the threshold value memory 12e, it is possible to adjust the sound quality of the voice data wirelessly communicated.

  Next, 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 voice flag 13a, a first DCL channel counter 13b, and a second DCL channel counter 13c.

  The voiced flag 13a is a flag for storing a determination result of a voice determination circuit 14 described later. In the voice flag 13 a, “1” is written by the sound determination circuit 14 when it is determined by the sound determination circuit 14 that the sound data includes a sound of a predetermined level or higher. In addition, when it is determined that the sound data includes only sound having a magnitude less than a predetermined level or does not include sound, “0” is written by the sound determination circuit 14.

  The voiced flag 13a is referred to during execution of the DCL communication process (see FIG. 5A) in the CPU 11, and is used in the DCL wireless communication 200 when the content of the voiced flag 13a is “1”. The DCL channel is determined by a good channel HP table stored in the first DCL channel memory 12b. On the other hand, when the content of the voiced flag 13 a is “0”, the DCL channel used in the wireless communication 200 by DCL is determined based on the determination result of the voice determination circuit 35 notified from the slave unit 31.

  Further, the content of the voiced flag 13a (that is, the determination result of the sound determination circuit 14) is notified to the slave unit 31 via the wireless communication 200 while the CPU 11 is executing the DCL communication process (see FIG. 5A). Is done.

  The first DCL channel counter 13b selects a DCL channel used in the DCL wireless communication 200 from the good channel HP table stored in the first DCL channel memory 12b according to the order indicated by the HP order 12b1 for each hopping cycle. It is a counter for doing. The CPU 11 refers to the first DCL channel counter 13b during execution of a DCL communication process (see FIG. 5A), which will be described later, from the good channel HP table to the HP order 12b1 indicated by the first DCL channel counter 13b. The corresponding HP channel 12b2 is selected.

  For example, in the case of the good channel HP table shown in FIG. 3A, if the first DCL channel counter 13b is “1”, the HP channel 12b2 “ch1” corresponding to the HP order 12b1 “1” is selected, If the 1DCL channel counter 13b is “2”, the HP channel 12b2 “ch3” corresponding to the HP order 12b1 “2” is selected.

  The first DCL channel counter 13b is updated during the DCL communication process executed by the CPU 11. That is, each time the good channel HP table (first DCL channel memory 12b) is accessed and the HP channel 12b2 is selected, the first DCL channel counter 13b is incremented by one. In addition, when the value reaches the number of DCL channels determined to have good communication conditions (“20” in the example of FIG. 3A), the first DCL channel counter 13b is set to “1”. Is set. Further, when the CPU 11 accesses the bad channel HP table (second DCL channel memory 12c) and selects the HP channel 12c2, the first DCL channel counter 13b is not updated. The first DCL channel counter 13b is initialized to “1” every time the good and bad channel HP tables are updated in the HP table generation processing executed by the CPU 11.

  The second DCL channel counter 13c determines the DCL channel used in the DCL wireless communication 200 from the bad channel HP table stored in the second DCL channel memory 12c according to the order indicated by the HP order 12c1 for each hopping cycle. This is a counter for selection. The CPU 11 refers to the second DCL channel counter 13c during execution of a DCL communication process (see FIG. 5A), which will be described later, and refers to the HP order 12c1 indicated by the second DCL channel counter 13c from the bad channel HP table. The HP channel 12c2 corresponding to is selected.

  For example, in the case of the bad channel HP table shown in FIG. 3B, if the second DCL channel counter 13c is “1”, the HP channel 12c2 “ch21” corresponding to the HP order 12c1 “1” is selected, If the second DCL channel counter 13c is “2”, the HP channel 12c2 “ch24” corresponding to the HP order 12c1 “2” is selected.

  Further, the second DCL channel counter 13c is updated during the DCL communication process executed by the CPU 11. That is, each time the HP channel 12c2 is selected by accessing the bad channel HP table (second DCL channel memory 12c), the second DCL channel counter 13c is incremented by one. Further, when the value reaches the number of DCL channels determined to have poor communication status (“25” in the example of FIG. 3B), the second DCL channel counter 13b is set to “1”. Is done. In addition, when the CPU 11 accesses the good channel HP table (first DCL channel memory 12b) and selects the HP channel 12b2, the second DCL channel counter 13c is not updated. The second DCL channel counter 13c is initialized to “1” every time the good and bad channel HP tables are updated during the HP table generation processing executed by the CPU 11.

  The voice determination circuit 14 includes voice data transmitted in the next hopping cycle among voice data transmitted from the MFP 1 to the child device 31 by the wireless communication 200 using DCL. A circuit for determining whether or not the audio data has a level greater than or equal to a predetermined level when the audio level included in the audio data is greater than or equal to the first threshold based on the content of the first threshold stored in the threshold memory 12e. Is determined to be included. Further, when the level of the sound included in the sound data is less than the first threshold value, it is determined that the sound data includes only sound having a magnitude less than the predetermined level or does not include sound.

  The voice determination circuit 14 performs voice determination when a voice determination instruction is issued from the CPU 11 by DCL communication processing (see FIG. 5A) executed by the CPU 11, and writes the determination result in the voiced flag 13a. That is, if it is determined that the sound data includes sound of a level equal to or higher than a predetermined level, “1” is written in the voiced flag 13a, and the sound data includes only sound of a level less than the predetermined level. If it is determined that no voice is included, “0” is written in the voiced flag 34a. When the voice determination circuit 14 finishes writing the determination result to the voice flag 13a, the voice determination circuit 14 notifies the CPU 11 of the end of the determination.

  The operation button 15 is an input button for setting various functions such as a DCL wireless communication function and a wireless LAN wireless communication function, and for instructing various operations. Further, by operating this operation button 15, the contents of the wireless LAN channel memory 12d and the first threshold value of the threshold value memory 12e can be changed.

  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 wireless LAN communication control circuit 17 includes a wireless LAN antenna 18 and configures various data while performing wireless communication 300 using the direct spreading method with the access point 51 having the wireless LAN antenna 51b. It is a circuit that transmits and receives digital signals. The wireless LAN communication control circuit 17 performs wireless communication 300 with the access point 51 using the wireless LAN channel stored in the wireless LAN channel memory 12d. When the wireless LAN channel is instructed from the access point 51, the wireless LAN channel is stored in the wireless LAN channel memory 12d of the RAM 13, and the access point 51 and the wireless communication 300 are connected using the wireless LAN channel. Do.

  The wireless LAN communication control circuit 17 also has a function of notifying the CPU 11 whether or not the wireless communication 300 using the wireless LAN is being performed. The CPU 11 inquires of the wireless LAN communication control circuit 17 about the operation state, so that the wireless LAN communication control circuit 17 notifies whether or not the wireless communication 300 using the wireless LAN is being performed.

  The DCL communication control circuit 19 has a DCL antenna 20, and performs a wireless communication 200 by a frequency hopping method with the DCL communication control circuit 39 of the slave unit 31, while making a digital signal ( Audio data). The DCL communication control circuit 19 performs wireless communication 200 with the slave unit 31 while using a DCL channel set in a later-described DCL communication process (see FIG. 5A) executed by the CPU 11 for each hopping cycle.

  The DCL communication control circuit 19 is provided with a reception electric field strength measurement circuit 19a. The reception electrolysis strength measurement circuit 19a receives the external electric field received from the DCL antenna 20 for the DCL channel (determination channel) designated by the CPU 11 when the wireless communication 200 is not performed with the slave unit 31. This is a circuit for measuring the intensity.

  When the CPU 11 designates a DCL channel (determination channel) to the DCL communication control circuit 19 during execution of an HP table generation process (see FIG. 4), which will be described later, the DCL communication control circuit 19 makes an external call from the DCL antenna 20. Receive radio waves. Then, the received electric field strength measuring circuit 19a measures the received electric field strength of the received external radio wave and notifies the CPU 11 of the measured received electric field strength. Then, the CPU 11 determines that the communication status of the DCL channel (determination channel) is good when the measured received electric field strength of the external radio wave is less than the second threshold, and the measured external radio wave received electric field. When the strength is greater than or equal to the second threshold, it is determined that the communication status of the DCL channel (determination channel) is not good.

  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 31 and received by the DCL communication control circuit 19 into an analog audio signal. Then, the data is output to the handset 23 and the NCU 25. Also, analog voice signals output when voice is input to the handset 23 and analog voice signals received by the NCU 25 from the external telephone 2 via the telephone network 100 are converted into digital signals (voice data). Then, the data is output to the DCL communication control circuit 19 and the voice determination circuit 14. The digital signal (audio data) input to the DCL communication control circuit 19 is transmitted to the slave unit 31 via the wireless communication 200. Also, the voice determination circuit 14 determines whether or not voice data transmitted in the next hopping cycle includes voice data of a predetermined level or more among voice data transmitted to the slave unit 31 via the wireless communication 200. To do.

  The NCU 25 is connected to the telephone line network 100, and transmits a dial signal to the telephone line network 100 and responds to a call signal from the telephone line network 100 to control a call with the external telephone 2. Is.

  Next, the detailed structure of the subunit | mobile_unit 31 is demonstrated. The handset 31 is a device for making a call with the MFP 1 and an external telephone 2 connected via the telephone line network 100 via the wireless communication 200 performed with the MFP 1.

  The subunit | mobile_unit 31 is provided with CPU32, EEPROM33, RAM34, the audio | voice determination circuit 35, the operation button 36, LCD37, the transmission / reception circuit 38, and the DCL communication control circuit 39. The CPU 32, EEPROM 33, and RAM 34 are connected to each other via a bus line 40. The voice determination circuit 35, the operation button 36, the LCD 37, the transmission / reception circuit 38, the DCL communication control circuit 39, and the bus line 40 are connected to each other via the input / output port 41.

  The CPU 32 controls each function of the slave unit 31 according to fixed values and programs stored in the EEPROM 33 and the RAM 34 or various signals transmitted and received via the DCL communication control circuit 39, and the input / output port 41. It is an arithmetic unit which controls each connected part.

  The EEPROM 33 is a rewritable nonvolatile memory storing a control program executed by the slave unit 31 and the like. A program for executing the DCL communication process shown in the flowchart of FIG. 5B is stored in the EEPROM 33. The EEPROM 33 is provided with a first DCL channel memory 33a, a second DCL channel memory 33b, and a threshold memory 33c.

  The first DCL channel memory 33a is a memory that stores the same good channel HP table as the first DCL channel memory 12b of the MFP1. The second DCL channel memory 33b is a memory that stores the same poor channel HP table as the second DCL channel memory 12c of the MFP 1. That is, the first DCL channel memory 33a stores the same good channel HP table as in FIG. 3A, and the second DCL channel memory 33b stores the same bad channel HP table as in FIG. 3B.

  These good and bad channel HP tables are generated at a predetermined interval (10 minute intervals) by the MFP 1 and then transmitted from the MFP 1 to the child device 31 via the wireless communication 200 by DCL. The subunit | mobile_unit 31 stores the transmitted good and bad channel HP table in the 1st and 2nd DCL channel memories 33a and 33b, respectively.

  Similarly to MFP 1, when wireless communication 200 of audio data including high-level audio is performed between MFP 1 and handset 31, the communication status is good in the order determined by the good channel HP table. Hopping is performed using the DCL channel determined to be present. Also, when wireless communication 200 of audio data including only low-level audio or not including audio is performed between the MFP 1 and the slave unit 31, the communication status is changed in the order determined by the bad channel HP table. Hopping is performed using a DCL channel determined to be not good.

  In other words, the CPU 32 performs wireless communication 200 of audio data including high-level audio between the MFP 1 and the slave unit 31 in the next hopping cycle during execution of a DCL communication process (see FIG. 5B) described later. When it is determined that the HP channel 12b is performed, the HP channel 12b2 of the HP order 12b1 indicated by the first DCL channel counter 34b described later is selected from the good channel HP table as the DCL channel to be used in the hopping cycle. If it is determined that wireless communication 200 of audio data including only low-level audio or not including audio is performed between the MFP 1 and the slave unit 31, the DCL channel used in the hopping cycle is The HP channel 12c2 of the HP order 12c1 indicated by the second DCL channel counter 34c described later is selected from the good channel HP table.

  As described above, when the handset 31 selects a DCL channel to be used in the next hopping cycle, the conditions selected from the good channel HP table and the conditions selected from the bad channel HP table are: Is the same as

  In addition, as described later, the first and second DCL channel counters 34b and 34c are updated under the same conditions as the first and second DCL channel counters 13b and 13c of the MFP 1. Therefore, in the same hopping cycle, the same DCL channel is always selected between the MFP 1 and the slave unit 31.

  The threshold value memory 33c is a memory for storing a first threshold value used in the sound determination circuit 35 described later. The first threshold is used to determine whether or not the sound data includes a sound having a level equal to or higher than a predetermined level when sound determination is performed by the sound determination circuit 35. Based on the content of the first threshold value stored in the threshold value memory 33c, the sound determination circuit 35 has a sound level greater than or equal to a predetermined level when the sound level included in the sound data is greater than or equal to the first threshold value. Is determined to be included. Further, when the level of the sound included in the sound data is less than the first threshold value, it is determined that the sound data includes only sound having a magnitude less than the predetermined level or does not include sound.

  The first threshold value is the same value as the first threshold value stored in the threshold memory 12e of the MFP 1. That is, the value obtained at the design stage for the first threshold value stored in the threshold value memory 12e of the MFP 1 is also stored in the threshold value memory 33c in advance. When the first threshold value stored in the threshold value memory 12 e of the MFP 1 is changed by an operation using the operation button 15, the changed value is notified from the MFP 1 to the slave unit 31 via the wireless communication 200. The subunit | mobile_unit 31 overwrites the value after this change notified to the threshold value memory 33. FIG. As a result, the determination level of the sound level in the sound determination circuit 14 of the MFP 1 is large / small (including no sound), and the sound level in the sound determination circuit 35 of the slave unit 31 is large / small (including no sound). The determination criteria can be the same.

  Next, the RAM 34 is a rewritable volatile memory, and is a memory for temporarily storing various data when each operation of the slave unit 31 is executed. The RAM 34 is provided with a voice flag 34a, a first DCL channel counter 34b, and a second DCL channel counter 34c.

  The voiced flag 34a is a flag for storing a determination result of a voice determination circuit 35 described later. In the voiced flag 34 a, “1” is written by the voice determination circuit 35 when the voice determination circuit 35 determines that the voice data includes a voice of a predetermined level or higher. In addition, when it is determined that the sound data includes only sound having a magnitude less than a predetermined level or does not include sound, “0” is written by the sound determination circuit 35.

  The voiced flag 34a is referred to during execution of the DCL communication process (see FIG. 5B) in the CPU 32. When the content of the voiced flag 34a is “1”, the voiced flag 34a is used in the DCL wireless communication 200. The DCL channel is determined by the good channel HP table stored in the first DCL channel memory 33a. On the other hand, when the content of the voiced flag 34 a is “0”, the DCL channel used in the DCL wireless communication 200 is determined based on the determination result of the sound determination circuit 14 notified from the MFP 1.

  Further, the content of the voice flag 34a (that is, the determination result of the sound determination circuit 35) is notified to the MFP 1 via the wireless communication 200 while the CPU 32 is executing the DCL communication process (see FIG. 5B). .

  The first DCL channel counter 34b selects the DCL channel used in the DCL wireless communication 200 from the good channel HP table stored in the first DCL channel memory 33a according to the order indicated by the HP order 12b1 for each hopping period. It is a counter for doing. The CPU 32 refers to the first DCL channel counter 34b during execution of a DCL communication process (see FIG. 5B), which will be described later, and changes from the good channel HP table to the HP order 12b1 indicated by the first DCL channel counter 34b. The corresponding HP channel 12b2 is selected.

  The first DCL channel counter 34b is updated during the DCL communication process executed by the CPU 32. That is, each time the good channel HP table (first DCL channel memory 33a) is accessed and the HP channel 12b2 is selected, the first DCL channel counter 34b is incremented by one. In addition, when the value reaches the number of DCL channels determined to have good communication conditions (“20” in the example of FIG. 3A), the first DCL channel counter 34b is set to “1”. Is set. On the other hand, when the CPU 32 accesses the bad channel HP table (second DCL channel memory 33b) and selects the HP channel 12c2, the first DCL channel counter 34b is not updated. The first DCL channel counter 34b is initialized to “1” every time the good and bad channel HP table is transmitted from the MFP 1.

  As described above, the conditions for accessing the good channel HP table and the conditions for accessing the no good channel HP table are the same as those for the MFP 1. Accordingly, the conditions for updating the first DCL channel counter 34b are the same as those of the first DCL channel counter 13b of the MFP 1. Accordingly, the first DCL channel counter 34b of the slave unit 31 and the first DCL channel counter 13b of the MFP 1 are updated synchronously.

  The second DCL channel counter 34c determines the DCL channel used in the DCL wireless communication 200 from the bad channel HP table stored in the second DCL channel memory 33b according to the order indicated by the HP order 12c1 for each hopping cycle. This is a counter for selection. The CPU 32 refers to the second DCL channel counter 34c during execution of a DCL communication process (to be described later) (see FIG. 5B) and refers to the HP order 12c1 indicated by the second DCL channel counter 34c from the bad channel HP table. The HP channel 12c2 corresponding to can be selected.

  Further, the second DCL channel counter 34c is updated during the DCL communication process executed by the CPU 32. That is, each time the HP channel 12c2 is selected by accessing the bad channel HP table (second DCL channel memory 33b), the second DCL channel counter 34c is incremented by one. When the value reaches the number of DCL channels determined to have poor communication conditions (“25” in the example of FIG. 3B), the second DCL channel counter 34c is set to “1”. Is done. Further, when the CPU 32 accesses the good channel HP table (first DCL channel memory 33a) and selects the HP channel 12b2, the second DCL channel counter 34c is not updated. The second DCL channel counter 34c is initialized to “1” every time the good and bad channel HP table is transmitted from the MFP 1.

  As described above, the conditions for accessing the good channel HP table and the conditions for accessing the no good channel HP table are the same as those for the MFP 1. Accordingly, the conditions for updating the second DCL channel counter 34c are the same as those of the second DCL channel counter 13c of the MFP 1. Accordingly, the second DCL channel counter 34c of the slave unit 31 and the second DCL channel counter 13c of the MFP 1 are updated in synchronization.

  The voice determination circuit 35 determines whether or not voice data transmitted in the next hopping cycle includes voice data of a predetermined level or more among voice data transmitted from the slave unit 31 to the MFP 1 by the DCL wireless communication 200. In the circuit for determining whether or not the level of the audio included in the audio data is greater than or equal to the first threshold based on the content of the first threshold stored in the threshold memory 33c, the audio data has a magnitude greater than or equal to a predetermined level. Is determined to be included. Further, when the level of the sound included in the sound data is less than the first threshold value, it is determined that the sound data includes only sound having a magnitude less than the predetermined level or does not include sound.

  The sound determination circuit 35 performs sound determination when an instruction for sound determination processing is received from the CPU 32 by DCL communication processing (see FIG. 5B) executed by the CPU 32, and writes the determination result in the voiced flag 34a. . That is, when it is determined that the sound data includes a sound of a level equal to or higher than a predetermined level, “1” is written in the voiced flag 34a, and the sound data includes only a sound of a level less than the predetermined level. If it is determined that no voice is included, “0” is written in the voiced flag 34a. When the voice determination circuit 35 finishes writing the determination result to the voice flag 34a, the voice determination circuit 35 notifies the CPU 32 of the end of the determination.

  The operation button 36 is an input button for instructing and setting various operations. The LCD 37 is a display device for displaying a menu, an operation state, and the like according to the operation of the operation button 36. When the user operates the operation button 36, information corresponding to the operation is displayed on the LCD 37.

  The transmission / reception circuit 38 is a circuit for making a call with the MFP 1 or an external telephone 2 connected to the MFP 1 via the telephone network 100. The transmission / reception circuit 38 includes a speaker and a microphone. The transmitter / receiver circuit 38 converts the digital signal transmitted from the MFP 1 and received by the DCL communication control circuit 39 into an analog audio signal, and outputs the sound from the speaker to the outside. In addition, the analog audio signal input from the microphone is converted into a digital signal (audio data) and output to the DCL communication control circuit 39 and the audio determination circuit 35. The digital signal (audio data) input to the DCL communication control circuit 39 is transmitted to the MFP 1 via the wireless communication 200. Also, the voice determination circuit 35 determines whether or not voice data transmitted in the next hopping cycle includes voice data of a predetermined level or more among voice data transmitted to the MFP 1 via the wireless communication 200. The

  The DCL communication control circuit 39 includes a DCL antenna 39a, and performs digital communication (voice data) that constitutes the voice of a call while performing wireless communication 200 by the frequency hopping method with the DCL communication control circuit 19 of the MFP 1. ). The DCL communication control circuit 39 performs wireless communication 200 with the MFP 1 using a DCL channel set in a later-described DCL communication process (see FIG. 5B) executed by the CPU 32 every hopping cycle.

  Next, with reference to FIG. 4, a processing flow of HP table generation processing executed in the MFP 1 will be described. FIG. 4 is a flowchart of HP table generation processing. This process is a process for generating a good channel HP table and a bad channel HP table, and is executed by the CPU 11 at intervals of 10 minutes.

  In the HP table generation process, first, it is determined whether the wireless communication 200 by DCL is being performed (S11). In the HP table generation processing, the DCL communication control circuit 19 is used to receive external radio waves and measure the received electric field strength of the external radio waves. Therefore, when performing wireless communication 200 by DCL, this HP table generation processing is performed. Cannot be executed. The process of S11 is a process intended to stop the HP table generation process in such a case, and when it is determined that the wireless communication 200 by DCL is performed in the process of S11 (S11: Yes), The HP table generation process is terminated.

  On the other hand, when it is determined that the wireless communication 200 by DCL is not performed (S11: No), the process proceeds to S12, and the generation of the HP table is started. In the process of S12, among the 89 DCL channels (ch1 to ch89) provided in the 2.4 GHz band, 45 DCL channels used for hopping (HP) of the wireless communication 200 by DCL are selected (S12). . Here, a plurality of selection patterns are prepared in advance in the EEPROM, and one selection pattern is selected from them, and 45 channels of DCL channels are selected. Alternatively, 45 DCL channels may be selected from 89 DCL channels at random.

  Next, one determination channel for determining whether or not the communication status is good is selected from the 45 DCL channels used for hopping (HP) (S13). Here, the DCL channel with the smallest channel number is selected from the DCL channels that have not yet been determined whether the communication status is good.

  Next, the wireless LAN communication control circuit 17 is inquired about the operating state, receives a notification from the wireless LAN communication control circuit 17 as to whether or not the wireless communication 300 is performed by the wireless LAN, and the MFP 1 performs wireless communication using the wireless LAN. It is determined whether the communication 200 is performed (S14).

  If it is determined that the wireless communication 200 by the wireless LAN is performed in the MFP 1 (S14: Yes), the wireless LAN channel used in the wireless LAN is read from the wireless LAN channel memory 12d, and the wireless LAN channel DCL channels with overlapping frequency bands are identified from the channel correspondence table (see FIG. 2) stored in the channel correspondence memory 12a, and the determination channel overlaps with the wireless LAN channel used in the wireless LAN. Is determined (S15).

  Here, when it is determined that the determination channel overlaps with the frequency band of the wireless LAN channel used in the wireless LAN (S15: Yes), the frequency band of the determination channel is used by the wireless LAN. It is determined that the situation is not good, and the process proceeds to S18.

  In this way, the determination channel that overlaps the frequency band of the wireless LAN channel used in the wireless communication 300 by the wireless LAN performed by the own apparatus (MFP 1) is determined as a channel in which the communication state is not good as it is. Can be easily determined. In addition, for the determination channel overlapping with the wireless LAN channel used in the wireless communication 300 by the wireless LAN, it is not necessary to actually measure the communication state of the determination channel, so the burden on determining the communication state is suppressed. be able to.

  On the other hand, if it is determined as a result of the process of S14 that the MFP 1 is not performing the wireless communication 200 by the wireless LAN (S14: No), and the result of the process of S15, the determination channel is the wireless used by the wireless LAN. When it is determined that it does not overlap with the frequency band of the LAN channel (S15: No), the determination channel is designated to the DCL communication control circuit 19. Then, according to the designation of the determination channel, it is determined whether the reception electric field intensity of the external radio wave of the determination channel measured by the reception electric field intensity measurement circuit 19a is less than the second threshold stored in the threshold memory 12e (S16). .

  Here, when it is determined that the received electric field intensity of the external radio wave of the determination channel is less than the second threshold (S16: Yes), it is not affected by the external radio wave, and therefore the communication status of the determination channel is good. Determination is made and the process proceeds to S17. On the other hand, when it is determined that the received electric field strength of the external radio wave measured in the determination channel is equal to or greater than the second threshold (S16: No), the external radio wave causes interference, so the communication status of the determination channel is good. If not, the process proceeds to S18. Thus, since it is determined whether or not the communication status of the determination channel is good according to the magnitude of the electric field strength of the external radio wave, the determination can be made with high accuracy.

  Subsequently, in the process of S17, the channel number of the determination channel determined to have a good communication status in the process of S16 is stored in the first DCL channel memory 12b, and the process proceeds to S19. On the other hand, in the process of S18, the determination channel determined to have a poor communication status in the processes of S15 and S16 is stored in the second DCL channel memory 12c, and the process proceeds to S19. Accordingly, the DCL channel determined to have a good communication status and the DCL channel determined to have a poor communication status can be classified into the first and second DCL channel memories 12b and 12c, respectively.

  In the process of S19, it is determined whether or not it has been determined whether or not the communication status is good for all 45 DCL channels used in the hopping (HP) selected in the process of S12. When it is determined that the communication status is not good in all the DCL channels for 45 channels (S19: No), the process returns to S13. As a result, the DCL channel having the smallest channel number among the DCL channels for which the determination as to whether the communication status is good is not performed again is used as the determination channel to determine whether the communication status is good. Is done.

  Then, in the process of S19, the processes of S13 to S19 are repeatedly executed until it is determined that the communication status is good in all the DCL channels for 45 channels (S19: Yes). . As a result, it is determined whether or not the communication status is good for all 45 DCL channels, and all the DCL channels determined to have good communication status are stored in the first DCL channel memory 12b. The On the other hand, all DCL channels determined to have poor communication conditions are stored in the second DCL channel memory 12c.

  As a result of the process of S19, if it is determined that the communication status is good in all 45 DCL channels (S19: Yes), the process loop of S13 to S19 is performed. The process proceeds to S20. In the process of S20, the DCL channels stored in the first DCL channel memory 12b, that is, the DCL channels determined to have good communication status are randomly rearranged to determine the hopping order (HP order). As a result, a good channel HP table as shown in FIG. 3A is generated and stored in the first DCL channel memory 12b.

  Next, the DCL channels stored in the second DCL channel memory 12c, that is, the DCL channels determined to have poor communication status are randomly rearranged to determine the hopping order (HP order) (S21). As a result, a bad channel HP table as shown in FIG. 3B is generated and stored in the second DCL channel memory 12c.

  Then, the good and bad channel HP tables stored in the first and second DCL channel memories 12b and 12c are transmitted to the slave unit 31 (S22). Thereby, the subunit | mobile_unit 31 can have a common HP table. Further, the values of the first and second DCL channel counters 13b and 13c are initialized to “1” (S23), and the HP table generation process is terminated.

  Next, a processing flow of DCL communication processing executed by the MFP 1 will be described with reference to FIG. FIG. 5A is a flowchart of DCL communication processing executed by the MFP 1. This process is a process for setting a DCL channel (hopping channel) to be used in the next hopping cycle on the MFP 1 side when performing wireless communication 200 by DCL, and is activated and executed by the CPU 11 for each hopping cycle.

  In this process, first, the voice determination circuit 14 receives the MFP 1 at the next hopping cycle out of the voice data input from the external telephone 2 via the telephone line network 100 or the voice data input from the handset 23. Is instructed to determine whether or not the audio data transmitted to the slave unit 31 includes audio data of a predetermined level or higher (S31). When a notification of determination completion is received from the voice determination circuit 14, the content of the voice flag 13a in which the determination result is written is confirmed, and it is determined whether the voice flag is “1” (S32).

  Here, when it is determined that the voiced flag 13a is “1” (S32: Yes), the voice determination circuit 14 transmits the voice data from the MFP 1 to the slave unit 31 in the next hopping cycle. Therefore, it is determined that voice data including high level voice is transmitted from the MFP 1 in the next hopping cycle to the slave unit 31 (S33). Move on to processing.

  On the other hand, when it is determined that the voice flag 13a is “0” as a result of the process of S32 (S32: No), the voice determination circuit 14 determines that the voice data transmitted in the next hopping cycle is less than a predetermined level. Therefore, it is determined that the voice data including only a low level voice is transmitted from the MFP 1 in the next hopping cycle. The process proceeds to S35) and S35.

  As described above, the voice data input from the external telephone 2 or the voice data input from the handset 23 via the telephone line network 100 is transmitted from the MFP 1 to the slave unit 31 at the next hopping cycle. Therefore, when the audio level included in the data transmitted from the MFP 1 is high, the slave unit 31 uses the good channel HP table. The DCL channel to be used in the next hopping cycle can be set.

  Next, in the process of S35, the audio data input from the microphone provided in the transmission / reception circuit 38 of the child device 31 is included in the sound data transmitted from the child device 31 to the MFP 1 in the next hopping cycle. Information on the level of the voice level is received from the slave unit 31, and based on the information, it is determined whether the voice level included in the voice data transmitted from the slave unit 31 is high (S35). And when it is judged that the level of the audio | voice contained in the audio | voice data transmitted from the subunit | mobile_unit 31 is large (S35: Yes), it transfers to the process of S36 and is contained in the audio | voice data transmitted from the subunit | mobile_unit 31. When it is determined that the sound level is low (S35: No), the process proceeds to S38.

  In S36, the HP channel 12b2 corresponding to the HP order 12b1 indicated by the first DCL channel counter 13b is selected from the good channel HP table stored in the first DCL channel memory 12b, and the selected HP channel is selected. 12b2 is set as a DCL channel to be used in the next hopping cycle and notified to the DCL communication control circuit 19.

  Thereby, in the next hopping cycle, at least one of the audio data transmitted from the MFP 1 to the child device 31 and / or the audio data transmitted from the child device 31 to the MFP 1 has a sound level equal to or higher than a predetermined level. Is included in the hopping cycle, the DCL wireless communication 200 can be performed between the MFP 1 and the slave unit 31 using the DCL channel determined to have good communication status. Therefore, audio data including high-level audio can be transmitted and received without noise or sound interruption.

  Next, the first DCL channel counter 13b is updated (S37), and the DCL communication process is terminated. That is, in the process of S37, the first DCL channel counter 13b is incremented by 1, or the value is the number of DCL channels determined to have good communication conditions (20 in the example of FIG. 3A). In this case, the first DCL channel counter 13b is set to “1”.

  As a result, when the audio data transmitted and received between the MFP 1 and the slave unit 31 includes audio of a predetermined level or higher, the HP channel 12b2 is sequentially set according to the order indicated by the HP order 12b1 by the good channel HP table. Will be selected.

  On the other hand, in the process of S38, the HP channel 12c2 corresponding to the HP order 12c1 indicated by the second DCL channel counter 13c is selected from the bad channel HP table stored in the second DCL channel memory 12c, and the selected HP is selected. The channel 12c2 is set as a DCL channel to be used in the next hopping cycle and notified to the DCL communication control circuit 19.

  As a result, in the next hopping cycle, both of the audio data transmitted from the MFP 1 to the slave unit 31 and the audio data transmitted from the slave unit 31 to the MFP 1 include only a voice less than a predetermined level. Alternatively, when voice is not included, in the hopping cycle, the DCL wireless communication 200 can be performed between the MFP 1 and the slave unit 31 using the DCL channel determined to have a poor communication state. Therefore, it is possible to prevent uselessly assigning a DCL channel having a good communication status to such audio data that does not require sound quality.

  Next, the second DCL channel counter 13c is updated (S39), and the DCL communication process is terminated. That is, in the process of S39, the second DCL channel counter 13c is incremented by 1, or the value is the number of DCL channels determined to have poor communication conditions (25 in the example of FIG. 3B). In this case, the second DCL channel counter 13c is set to “1”.

  As a result, when the audio data transmitted / received between the MFP 1 and the slave unit 31 includes only audio of less than a predetermined level or does not include audio, it is indicated by the HP order 12c1 by the bad channel HP table. The HP channel 12c2 is sequentially selected according to the order.

  Next, with reference to FIG. 5B, a processing flow of DCL communication processing executed by the slave unit 31 will be described. FIG. 5B is a flowchart of the DCL communication process executed by the slave unit 31. This process is a process for setting a DCL channel (hopping channel) to be used in the next hopping cycle on the side of the slave unit 31 when performing wireless communication 200 by DCL, and is activated and executed by the CPU 32 for each hopping cycle.

  In this process, first, the voice data input from the microphone provided in the transmission / reception circuit 38 of the handset 31 is transmitted to the voice determination circuit 35 from the handset 31 to the MFP 1 in the next hopping cycle. It is instructed to determine whether or not the audio data includes audio data of a predetermined level or higher (S41). Then, when a notification of determination completion is received from the voice determination circuit 35, the content of the voice flag 34a in which the determination result is written is confirmed, and it is determined whether the voice flag is “1” (S42).

  Here, when it is determined that the voiced flag 34a is “1” (S42: Yes), the voice determination circuit 35 transmits the voice data from the slave unit 31 to the MFP 1 in the next hopping cycle. Therefore, it is determined that voice data including a high level is transmitted from the slave unit 31 to the MFP 1 in the next hopping cycle (S43). Move on to processing.

  On the other hand, if it is determined as a result of the processing of S42 that the voice flag 34a is “0” (Y42: No), the voice determination circuit 35 determines that the voice data transmitted in the next hopping cycle is less than a predetermined level. Therefore, it is determined that voice data including only a low level voice is transmitted from the slave unit 31 to the MFP 1 in the next hopping cycle. S44) and the process proceeds to S45.

  As described above, of the voice data input from the microphone provided in the transmission / reception circuit 38 of the handset 31 to the MFP 1, the voice included in the voice data transmitted from the handset 31 in the next hopping cycle. Since the large / small information of the level is transmitted, in the MFP 1, when the level of the sound included in the data transmitted from the slave unit 31 is large, the DCL channel to be used in the next hopping cycle according to the good channel HP table. Can be set.

  Next, in the process of S45, from the voice data input from the external telephone 2 via the telephone line network 100 or the voice data input from the handset 23, from the MFP 1 to the slave unit 31 in the next hopping cycle. The information on the audio level included in the audio data to be transmitted is received from the MFP 1 and based on the information, it is determined whether the audio level included in the audio data transmitted from the MFP 1 is high (S45). . If it is determined that the level of audio included in the audio data transmitted from the MFP 1 is high (S45: Yes), the process proceeds to S46, and the level of audio included in the audio data transmitted from the MFP 1 is determined. When it is determined that the value is smaller (S45: No), the process proceeds to S48.

  In S46, the HP channel 12b2 corresponding to the HP order 12b1 indicated by the first DCL channel counter 34b is selected from the good channel HP table stored in the first DCL channel memory 33a, and the selected HP channel is selected. 12b2 is set as a DCL channel to be used in the next hopping cycle and notified to the DCL communication control circuit 39.

  Thereby, in the next hopping cycle, at least one of the audio data transmitted from the MFP 1 to the child device 31 and / or the audio data transmitted from the child device 31 to the MFP 1 has a sound level equal to or higher than a predetermined level. Is included in the hopping cycle, the DCL wireless communication 200 can be performed between the MFP 1 and the slave unit 31 using the DCL channel determined to have good communication status. Therefore, audio data including high-level audio can be transmitted and received without noise or sound interruption.

  Next, the first DCL channel counter 34b is updated (S47), and the DCL communication process is terminated. That is, in the process of S47, the first DCL channel counter 34b is incremented by 1, or the value is the number of DCL channels determined to have good communication conditions (20 in the example of FIG. 3A). In this case, the first DCL channel counter 34b is set to “1”.

  As a result, when the audio data transmitted and received between the MFP 1 and the slave unit 31 includes audio of a predetermined level or higher, the HP channel 12b2 is sequentially set according to the order indicated by the HP order 12b1 by the good channel HP table. Will be selected.

  On the other hand, in the process of S48, the HP channel 12c2 corresponding to the HP order 12c1 indicated by the second DCL channel counter 34c is selected from the bad channel HP table stored in the second DCL channel memory 33b, and the selected HP is selected. The channel 12c2 is set as a DCL channel to be used in the next hopping cycle and notified to the DCL communication control circuit 39.

  As a result, in the next hopping cycle, both of the audio data transmitted from the MFP 1 to the slave unit 31 and the audio data transmitted from the slave unit 31 to the MFP 1 include only a voice less than a predetermined level. Alternatively, when voice is not included, in the hopping cycle, the DCL wireless communication 200 can be performed between the MFP 1 and the slave unit 31 using the DCL channel determined to have a poor communication state. Therefore, it is possible to prevent uselessly assigning a DCL channel having a good communication status to such audio data that does not require sound quality.

  Next, the second DCL channel counter 34c is updated (S49), and the DCL communication process is terminated. That is, in the process of S49, the second DCL channel counter 34c is incremented by 1, or the value is the number of DCL channels determined to have a poor communication status (25 in the example of FIG. 3B). In this case, the second DCL channel counter 34c is set to “1”.

  As a result, when the audio data transmitted / received between the MFP 1 and the slave unit 31 includes only audio of less than a predetermined level or does not include audio, it is indicated by the HP order 12c1 by the bad channel HP table. The HP channel 12c2 is selected in order according to the order.

  As described above, according to the present embodiment, at least one of the audio data transmitted from the MFP 1 to the child device 31 and the sound data transmitted from the child device 31 to the MFP 1 is equal to or higher than a predetermined level. Is included, the wireless communication is performed via the DCL channel having a good communication state, so that the voice data can be transmitted and received without noise or sound interruption. On the other hand, both the audio data transmitted from the MFP 1 to the slave unit 31 and the audio data transmitted from the slave unit 31 to the MFP 1 include only audio less than a predetermined level or no audio. Since wireless communication is performed via a DCL channel having a poor communication status, it is possible to prevent a DCL channel having a good communication status from being unnecessarily assigned to audio data for which sound quality is not required. As a result, even when there are many DCL channels with poor communication conditions, the number of DCL channels (for 45 channels) required for performing DCL wireless communication 200 including DCL channels with poor communication conditions. ) Can be performed with high sound quality.

  Further, for each hopping period, the level of the voice level included in the voice data in which the wireless communication 200 is performed between the MFP 1 and the slave unit 31 in the next hopping period is detected, and the communication status is determined according to the detection result. Since the used channel used in the wireless communication 200 is set for each hopping period from one of the DCL channel with good communication status and the DCL channel with poor communication status, according to the sound level that changes every moment, An appropriate channel can be set as a use channel from a DCL channel with good communication status and a DCL channel with poor communication status. As a result, it is possible to efficiently use the 45 channels of DCL channels reserved for performing the DCL wireless communication 200 including the DCL channels with poor communication conditions. Further, since the voice determination circuits 14 and 35 detect in advance whether or not the volume of the voice included in the voice data to be communicated in the next hopping cycle is equal to or more than the first threshold value, the hopping cycle is short. However, according to the detection result, the used channel used in the hopping cycle can be set without delay from one of the DCL channel having a good communication status and the DCL channel having a poor communication status.

  Further, voice data input to the MFP 1 from the external telephone 2 via the telephone line network 100 or voice data input to the MFP 1 from the handset 23 and a microphone provided in the transmitter / receiver circuit 38 from the child. Whether to use a DCL channel with a good communication status or a DCL channel with a poor communication status is set based on the volume of audio included in both of the audio data input to the device 31. Therefore, even when voice data is wirelessly communicated between the MFP 1 and the slave unit 31 in both directions, it is necessary to perform the DCL wireless communication 200 including the DCL channel in which the communication state is not good. While securing the number of DCL channels (for 45 channels), wireless voice data communication can be performed with high sound quality between the MFP 1 and the slave unit 31 that communicate bidirectionally.

  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, in the above embodiment, the case where the wireless communication system T wirelessly communicates audio data by DCL has been described. However, the present invention is not necessarily limited to this, and the wireless data may be wirelessly communicated by other methods. Good. In this case, instead of the DCL communication control circuits 19 and 39, the MFP 1 and the slave unit 31 may each be provided with a communication control circuit corresponding to the method.

  In the above embodiment, the case where the wireless communication system T is equipped with a wireless communication function using a wireless LAN has been described. However, the present invention is not necessarily limited to this, and instead of or in addition to the wireless communication function using a wireless LAN. Thus, a wireless communication function by other methods may be installed. In this case, the MFP 1 may be provided with a communication control circuit corresponding to other methods. In addition, when at least a part of the frequency band used in the other system overlaps with the frequency band used in the DCL, the channel corresponding to the DCL channel overlapping with the frequency band of the radio channel used in the other system When a table is prepared and a good and bad channel HP table used in DCL is generated, referring to the channel correspondence table, a DCL channel overlapping with a radio channel used in other methods is indicated by the communication status. It may be determined that the channel is not good.

  For example, as a wireless communication function based on other methods, a wireless communication function based on Bluetooth may be installed in the wireless communication system T. Bluetooth performs wireless communication by frequency hopping using 89 Bluetooth channels having the same frequency band as each DCL channel. When the wireless communication system T is equipped with a wireless communication function based on Bluetooth, the MFP 1 may be provided with a communication control circuit corresponding to Bluetooth. In addition, among the 89 Bluetooth channels, a Bluetooth channel memory that stores a Bluetooth channel that is actually used as a hopping channel is provided, and when generating a good and bad channel HP table to be used in DCL, the Bluetooth channel memory is used. Referring to the DCL channel that uses the same frequency band as the Bluetooth channel stored in the Bluetooth channel memory, it may be determined that the communication status is not good.

  In the above embodiment, when determining the communication status of a DCL channel, a case has been described in which it is determined whether the communication status is good based on the received electric field strength of an external radio wave received on the DCL channel. However, the present invention is not limited to this, and the communication status may be determined based on a bit error rate (BER). In this case, a BER measurement circuit may be provided in the DCL communication control circuit 19 of the MFP 1 and a BER measurement radio wave transmission circuit may be provided in the DCL communication control circuit 39 of the slave unit 31. When determining the communication status of the DCL channel, the BER measurement radio wave transmission circuit of the slave unit 31 is transmitted using the DCL channel to be determined, and the DCL communication control circuit 19 of the MFP 1 transmits the BER measurement radio wave. It is only necessary to receive radio waves and measure the BER of the radio waves received by the BER measurement circuit. Here, if the measured BER is less than a predetermined level, it is determined that the communication status of the DCL channel to be determined is good, and if the BER is equal to or higher than the predetermined level, it is determined that the DCL channel is not in good communication status. be able to.

  In the above embodiment, the MFP 1 is provided with the first and second DCL channel counters 13b and 13c, and the slave unit 31 is provided with the first and second DCL channel counters 34b and 34c. The HP channel 12b2 in the HP order 12b1 indicated by the first DCL channel counters 13b and 34b of the machine 31 is selected, and the bad channel HP table is displayed in the HP order 12c1 indicated by the second DCL channel counters 13c and 34c of the MFP 1 and the slave unit 31. However, the present invention is not necessarily limited to this, and only one DCL channel counter may be provided in each of the MFP 1 and the slave unit 31. In this case, the DCL channel counter may be updated every hopping cycle, and the good and bad channel HP table may select the HP channels 12b2 and 12c2 of the HP order 12b1 and 12c1 indicated by the DCL channel counter. As a result, the control for selecting the HP channel can be simplified, and the control burden can be reduced.

  Further, in the above embodiment, in the HP table generation processing, 45 DCL channels for 45 channels used for hopping of the wireless communication 200 by DCL are selected from 89 DCL channels (ch1 to ch89), and the 45 channels. Although the case where it is determined whether or not the communication status is good for the DCL channel has been described, it is not necessarily limited to this, and it is determined whether or not the communication status is good for the 45 or more DCL channels. Also good. For example, it may be determined whether the communication status is good for all 89 DCL channels (ch1 to ch89). Then, a predetermined channel number (for example, 25 channels) is selected from the DCL channels determined to have good communication conditions to generate a good channel HP table, and the DCL channels determined to have poor communication conditions Therefore, the number of remaining channels necessary for hopping (for example, 20 channels) may be selected to generate a bad channel HP table.

  Alternatively, the good channel HP table may be generated using all DCL channels determined to have good communication conditions. If the number of DCL channels determined to have a good communication status is less than 45 channels necessary for hopping, the number of DCL channels that are insufficient from the DCL channels determined to have a poor communication status (Ie, the number obtained by subtracting the number of DCL channels determined to be good from “45”) may be selected, and the bad channel HP table may be generated from the selected DCL channel.

  In the above embodiment, the threshold value is set to the first threshold value (threshold value used in the sound determination of the sound determination circuits 14 and 35) corresponding to the number of DCL channels included in the good channel HP table. A table storing power values is stored in the EEPROM 12, and the CPU 11 changes the first threshold stored in the threshold memory 12e in accordance with the number of DCL channels included in the good channel HP table. Good. For example, the first threshold value may be changed so as to decrease as the number of DCL channels included in the good channel HP table increases. As a result, the amount of voice data wirelessly communicated using the DCL channel determined to have a good communication state increases, so that the more DCL channels that are determined to have a good communication state, the more wireless communication is performed. The sound quality of audio data can be improved. When the number of DCL channels included in the good channel HP table is 45, if the first threshold is set to “0”, it is determined that the communication status is good for all audio data. Wireless communication can be performed using the DCL channel.

It is the figure which showed the electric constitution of the radio | wireless communications system in one Embodiment of this invention. It is the schematic diagram which showed the content of the channel corresponding | compatible table typically. (A) is the schematic diagram which showed typically an example of the content of a good channel HP table, (b) is the schematic diagram which showed typically an example of the content of a bad channel HP table. 6 is a flowchart showing HP table generation processing executed in the MFP. (A) is a flowchart showing a DCL communication process executed by the MFP, and (b) is a flowchart showing a DCL communication process executed by the slave unit. It is the schematic which showed the frequency band and frequency channel which are used by wireless LAN and DCL.

Explanation of symbols

T wireless communication system ch1 to ch89 DCL channel (an example of a first wireless channel)
wch1 to wch14 Wireless LAN channel (example of second wireless channel)
1 MFP (example of base unit)
2 Telephone (example of external device)
12b First DCL channel memory (an example of first storage means)
12c Second DCL channel memory (an example of second storage means)
14 Voice determination circuit (an example of voice detection means)
15 operation buttons (an example of sound detection threshold value changing means)
17 Wireless LAN communication control circuit (an example of second wireless communication means)
19 DCL communication control circuit (an example of first wireless communication means and external radio wave detection means)
19a Received electric field strength measuring circuit (an example of electric field strength measuring means)
31 Slave unit 38 Transmission / reception circuit (an example of a microphone)
100 Telephone network (an example of a telephone line)
S15 (an example of specifying means)
S15: Yes (an example of communication status determination means)
S16 (an example of communication status determination means)
S36, S38 (an example of setting means)
S46, S48 (an example of setting means)

Claims (6)

In a wireless communication system including first wireless communication means for performing wireless wireless voice data communication using at least one first wireless channel among a plurality of first wireless channels provided in a predetermined frequency band,
Communication status determination means for determining whether or not the communication status of each of the plurality of first radio channels is good for each first radio channel;
First storage means for storing the first wireless channel determined to have good communication status by the communication status determination means;
Second storage means for storing the first wireless channel determined by the communication status determination means to be unsatisfactory,
Voice detecting means for detecting whether or not the volume of the voice included in the voice data communicated by the first wireless communication means is equal to or greater than a first threshold;
When the sound detection means detects that the sound volume included in the sound data is greater than or equal to the first threshold, at least one of the first wireless channels stored in the first storage means When the channel is set as a channel used by one wireless communication unit, and the voice detection unit detects that the volume of the voice included in the voice data is less than the first threshold, the second storage unit A wireless communication system comprising: setting means for setting at least one of the stored first wireless channels as the use channel. An external radio wave detecting means for detecting an external radio wave for each first radio channel for a part or all of the plurality of first radio channels;
Electric field strength measuring means for measuring the electric field strength of the external radio wave detected by the external radio wave detecting means for each of the first wireless channels,
The communication status judging means judges that the communication status is good for the first wireless channel whose electric field strength measured by the electric field strength measuring means is less than a second threshold, and measured by the electric field strength measuring means. The wireless communication system according to claim 1, wherein the wireless communication system determines that the communication status is not good for the first channel whose electric field strength is equal to or greater than a second threshold. Second wireless communication means for performing wireless communication using a second wireless channel whose frequency band overlaps with a part of the predetermined frequency band used by the first wireless communication means;
Identifying the first radio channel having a frequency band overlapping with the frequency band of the second radio channel used by the second radio communication unit among the plurality of first radio channels used by the first radio communication unit Specific means to
The communication status determining means determines that the communication status is not good for the first radio channel specified by the specifying means as having a frequency band overlapping with the frequency band of the second radio channel. The wireless communication system according to claim 1.   The radio communication system according to any one of claims 1 to 3, further comprising voice detection threshold value changing means for changing the first threshold value in the voice detection means. The first wireless communication means changes a first wireless channel used at a predetermined cycle,
The voice detection means detects whether or not the volume of the voice included in the voice data communicated by the first wireless communication means in the next predetermined cycle is equal to or greater than a first threshold;
When the setting means detects that the sound level included in the sound data to be communicated by the first wireless communication means at the next predetermined cycle by the sound detection means is not less than the first threshold, In the next cycle, one of the first radio channels stored in the first storage unit is set as a use channel to be used by the first radio communication unit, and the first radio channel is used in the next predetermined cycle. When it is detected that the volume of the voice included in the voice data communicated by the communication means is less than the first threshold value, in the next cycle, the first wireless channel stored in the second storage means 5. The wireless communication system according to claim 1, wherein one channel is set as the use channel. A master unit connected to an external device via a telephone line;
A microphone, and a slave unit that performs voice data communication with the master unit by the first wireless communication unit;
The voice detection means detects whether or not the volume of the voice included in the voice data input from the external device is equal to or greater than the first threshold, and detects the voice data input from the microphone of the slave unit. Detecting whether the volume of the included speech is equal to or greater than the first threshold;
The setting means is either one of a loudness level contained in the voice data inputted from the external device by the voice detection means and a loudness level contained in the voice data inputted to the microphone of the slave unit. Is detected as being equal to or greater than the first threshold value, one of the first wireless channels stored in the first storage means is set as a use channel used by the first wireless communication means, and It has been detected that both the volume of the voice included in the voice data input from the external device and the volume of the voice included in the voice data input to the microphone of the slave unit are less than the first threshold value. In this case, one of the first radio channels stored in the second storage means is set as the use channel. Wireless communication system of crab according.

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