JP4544012B2 - Wireless communication device - Google Patents

Description

  The present invention relates to a wireless communication technique, and more particularly to a spread spectrum modulation type frequency hopping technique used in a general-purpose wireless interface such as Bluetooth (registered trademark: Bluetooth).

In Bluetooth, which is a general-purpose wireless interface (see Non-Patent Document 1, etc.), a frequency hopping spread spectrum (FHSS) modulation method is used as a modulation method. The frequency hopping spread spectrum modulation system is a system in which the carrier frequency is changed at fixed time intervals, that is, the frequency hopping is performed for transmission.
In general, the power of any bandwidth is low when averaged over a sufficiently long time with respect to the frequency hopping period, so it is difficult to interfere with communication of other systems, and even if there is an interference wave at a specific frequency, It is said that it is resistant to interference from other systems because it hops to a frequency.

  In Bluetooth, 79 or 23 channels are provided in the 2.4 GHz band at 1 MHz intervals, and frequency hopping is performed at a rate of 1600 times / second based on the channel selection order set between the master side and the slave side at the start of communication. Repeatedly, data communication is performed by transmitting / receiving a desired packet to / from the counterpart wireless device using the selected channel.

Conventionally, as such a frequency hopping technique, when an arbitrary channel cannot be used due to radio waves transmitted from other devices, an adaptive frequency hopping (hereinafter referred to as AFH: Adaptive Frequency Hopping) technique for disabling the channel is available. Used (for example, see Non-Patent Document 2 etc./Bluetooth 1.2).
According to this adaptive frequency hopping technique, a channel determined to be unusable is excluded from the channel selection order, so that frequency hopping is no longer performed on the channel, and other channels at the carrier frequency of the channel Wireless communication interruption due to mutual interference of radio waves and collision of packet transmission / reception in the channel with the same type of wireless communication apparatus can be reduced.

www.bluetooth.org/spec/ www.ericsson.com/bluetooth/files/whitepaper_on_afh_final.pdf

  However, since such a conventional technique only performs passive control of not selecting a channel determined to be unusable by subsequent frequency hopping, the number of channels is set so that a desired communication quality can be obtained for data communication. There was a problem that it could not be increased or decreased.

  For example, in the frequency hopping spread spectrum modulation system, when the number of channels that cannot be used increases, the communication bandwidth of the entire data communication becomes narrow, resulting in a decrease in communication speed, that is, a decrease in communication quality. In particular, in the case of voice communication, it causes noise to the voice signal and causes voice quality degradation. Moreover, although the number of usable channels is reduced, if transmission power is reduced, the influence on other wireless communications can be reduced, and the communication band can be shared efficiently. Furthermore, the power consumption can be suppressed by reducing the wireless output level, and the operation time can be extended by suppressing the power consumption in a wireless communication terminal that operates with a secondary power source such as a battery. Therefore, it is important to perform data communication using an appropriate number of channels according to desired communication quality.

  An object of the present invention is to provide a wireless communication apparatus and method capable of performing data communication using an appropriate number of channels according to desired communication quality. Yes.

In order to achieve such an object, a wireless communication device according to the present invention is connected to a partner wireless device via a wireless line, and sequentially selects a plurality of channels having different carrier frequencies according to a predetermined channel selection order. A wireless communication device that performs data communication with a partner wireless device by transmitting and receiving a desired packet using the selected channel, and disables the channel when a packet transmission / reception error occurs in any channel. A storage unit that stores a channel table that manages the availability of each channel and an output level table that manages the wireless output level of each channel, and receives packets from the counterpart wireless device using the selected channel. , To the counterpart wireless device at the wireless output level of the channel set in the output level table A wireless transceiver for transmitting a packet, and a communication control unit for transmitting and receiving packets by the wireless transceiver sequentially selects a channel showing a usable from the channel table according to the channel selection order when the data communication has been notified from the other wireless device Channel management means for confirming the presence / absence of an error in packet transmission / reception on the channel based on the confirmation status indicating the packet reception status on an arbitrary channel, and setting the availability of the channel in the channel table according to the confirmation result ; When the number of usable channels used for data communication obtained from the channel table is smaller than a predetermined reference value, it is determined that the number of usable channels is insufficient, the number of usable channels is equal to or greater than the reference value, and determines that the number of available channels is excessive if more than a predetermined upper limit value, these And an output level control means on the basis of excessive lack of use can the number of channels by adjusting the radio output level of the channel is set to the output level table, the output level control unit, the channel status indicating the shortage of the number of available channels In this case, the wireless output level of the unusable channel is increased, and when the channel status indicates an excessive number of usable channels, the wireless output level of the usable channel is decreased.

  Also, when confirming whether or not a channel can be used, the channel management unit notifies the partner wireless device of the channel to be checked when data communication is not being performed with the partner wireless device, and then the channel is checked. The confirmation packet may be transmitted / received to / from the counterpart wireless device, and the availability of the channel may be confirmed according to whether or not an error has occurred.

According to the present invention, the channel management means confirms whether or not the channel can be used according to whether or not an error occurs in packet transmission / reception in an arbitrary channel, and the number of usable channels and the reference value obtained from the confirmation result are obtained. When it is determined that the number of usable channels is excessive or insufficient, and the output level control means indicates that the channel status indicates an insufficient number of usable channels, the wireless output level of the unusable channel is increased and the channel status is determined to be usable. In the case of an excessive number of channels, the radio output level of the wireless transmission / reception unit is adjusted by reducing the radio output level of the usable channels, so the number of usable channels can be increased or decreased, and the appropriate number according to the desired communication quality. Data communication can be performed using any number of channels.

As a result, when the number of usable channels is insufficient, the output level of the unusable channels is increased so that the channels with improved radio wave environment can be used. Thereby, the number of usable channels can be increased as a whole, and desired communication quality can be obtained.
In addition, when the number of usable channels is excessive, by reducing the output level of the usable channels, the channels cannot be used in channels in which the radio wave environment has deteriorated. Thereby, it is possible to reduce the transmission power corresponding to the desired communication quality as a whole, reduce the influence on other wireless communication, and share the communication band efficiently. Furthermore, the power consumption can be suppressed by reducing the wireless output level, and the operation time can be extended by suppressing the power consumption in a wireless communication terminal that operates with a secondary power source such as a battery.

Next, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, a radio communication apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the wireless communication apparatus according to the first embodiment of the present invention.
The wireless communication device (master side) 1 is connected to a partner wireless device (slave) via a wireless line 3 based on the frequency hopping spread spectrum (FHSS) modulation method of the Bluetooth (registered trademark) wireless communication method. Side) 2 is a terminal device that realizes various functions by performing wireless data communication, and includes a wireless module 11, a function processing unit 15, and a host control unit 16.

  In the present embodiment, the channel management means of the wireless communication apparatus 1 confirms the channel status indicating whether each channel used in the cycle hopping is available, and the output level control means checks the available channel excess indicated by the channel status. The radio output level of each channel is controlled according to the shortage.

Hereinafter, the configuration of the wireless communication device 1 will be described in detail with reference to FIG.
The wireless module 11 is a functional module that provides a wireless interface compliant with the Bluetooth wireless communication system, and various functional units are integrally mounted as one component constituting the wireless communication device 1.
The main functional units provided in the wireless module 11 include a wireless transmission / reception unit 12, a module storage unit 13, and a module control unit 14.

  The wireless transmission / reception unit 12 is a circuit unit that transmits / receives a wireless signal in accordance with the Bluetooth wireless communication system, and performs a data communication via the wireless line 3 by transmitting / receiving a wireless signal to / from the counterpart wireless device 2. And a function of transmitting a radio signal at an arbitrary radio output level when transmitting a radio signal. At this time, the radio transmission / reception unit 12 repeats frequency hopping based on an instruction from the module control unit 14 for 79 channels or 23 channels provided in the 2.4 GHz band at 1 MHz intervals based on the frequency hopping spread spectrum modulation method. Data communication is performed by transmitting / receiving a desired packet to / from the counterpart wireless device 2 using the channel selected by the frequency hopping.

The module storage unit 13 includes a storage device such as a memory, and has a function of storing various processing information used for processing operations in the module control unit 14. Main processing information stored in the module storage unit 13 includes a channel table 13A and an output level table 13B.
The channel table 13A is processing information for managing the availability of each channel that is sequentially selected by the frequency hopping spread spectrum modulation method, and the availability information of the channel corresponds to each channel number as shown in FIG. It is registered with it.

The output level table 13B is processing information for controlling the wireless output level in the wireless transmission / reception unit 12, and as shown in FIG. 3, each wireless output level is registered as a set for each channel. Here, the radio output level is set according to the output level corresponding to the actual output power.
In addition, the module storage unit 13 may store a program for realizing various functional units by being read and executed by the module control unit 14 in advance.

  The module control unit 14 cooperates with hardware composed of a CPU and its peripheral circuits, a memory (not shown) provided in these CPUs or peripheral circuits, and a program stored in the module storage unit 13 in advance. A functional unit for controlling the wireless transmission / reception unit 12 in accordance with the Bluetooth wireless communication system is realized.

As main functional means realized by the module control unit 14, there is a communication control means 14A.
The communication control unit 14A controls the wireless transmission / reception unit 12 to control data communication between the partner wireless device 2 and the host control unit 16, and the partner wireless device 2 based on the frequency hopping / spread spectrum modulation method. One of the channels is sequentially selected based on the order of channel selection decided at the time of starting data communication between the two and wireless transmission / reception together with the wireless output level of the channel obtained from the output level table 13B of the module storage unit 13 And a function for instructing the unit 12. At this time, the communication control unit 14A refers to the channel table 13A of the module storage unit 13 and skips to the next available channel when the next channel selected according to the channel selection order is unavailable. Select the channel.

  In addition, the communication control unit 14A notifies the host control unit 16 of the communication status of packet transmission / reception with the counterpart wireless device 2 on the channel selected by frequency hopping during data communication, and in response to an instruction from the host control unit 16. Correspondingly, the channel table 13A of the module storage unit 13 is notified of the channel table 13A of the module storage unit 13 according to the function of updating the availability information of an arbitrary channel and the instruction from the host control unit 16 to the counterpart wireless device 2. And a function of notifying the partner wireless device 2 and updating the wireless output level of each channel or the output level table 13B of the module storage unit 13 in accordance with an instruction from the host control unit 16. .

  Further, the communication control unit 14A transmits a free channel confirmation request packet or a free confirmation packet to the counterpart wireless device 2 using a channel designated by the host control unit 16 separately from the channel selection order of frequency hopping. The host control unit 16 indicates the function of receiving the empty channel confirmation request response packet and the empty confirmation response packet returned from the counterpart wireless device 2 in response to these packets, and the communication status of the empty channel confirmation request response packet and the empty confirmation response packet. It has a function to notify.

  The function processing unit 15 has a function of providing various functions of the wireless communication device 1 based on control from the host control unit 16, for example, various terminal functions such as voice call, content display, settlement, and data management.

The host control unit 16 provides a desired terminal function by cooperating hardware including a CPU or its peripheral circuit and a program stored in advance in the CPU or a memory provided in the peripheral circuit. Implement various functional means.
As main functional means realized by the host control unit 16, there are a data communication means 16A, a channel management means 16B, and an output level control means 16C.

The data communication unit 16 </ b> A has a function of performing data communication with the counterpart wireless device 2 via the wireless module 11.
The channel management unit 16B determines whether or not each channel can be used according to the communication status from the wireless module 11, and instructs the wireless module 11 to update the channel table 13A as necessary. A function for instructing reconfirmation of the availability with the counterpart wireless device 2 and a function for instructing the radio module 11 to reconfirm the availability with the counterpart radio device 2 regarding the unusable channel at a predetermined cycle. And a function of instructing the wireless module 11 to update notification of the channel table 13A to the counterpart wireless device 2 in accordance with the update of the channel table 13A.

  At this time, the channel management means 16B notifies the channel to be confirmed between the two by transmitting the empty channel confirmation request packet shown in FIG. 4 from the wireless module 11 to the counterpart wireless device 2, and the empty confirmation packet shown in FIG. Is transmitted from the wireless module 11 to the counterpart wireless device 2 and a free confirmation response packet is received from the counterpart wireless device 2 accordingly, thereby confirming whether the channel is available, that is, whether it can be used.

  The free channel confirmation request packet of FIG. 4 is provided with an access code 200 comprising information on synchronization and options, a header 201 for storing the packet address and control information, and a payload 202 for storing desired data to be transmitted in the packet. In this payload 202, a command 203 indicating that the packet is a command for requesting an empty channel confirmation, and a designated channel number 204 indicating a channel to be confirmed between them are described. Since the channel to be checked is different from the channel selection order in frequency hopping in normal data communication, it is mutually confirmed that this channel is temporarily selected in the next frequency hopping using this packet.

  In addition, the empty confirmation packet in FIG. 5 is provided with an access code 210 including information on synchronization and options, a header 211 for storing packet address and control information, and a payload 212 for storing desired data to be transmitted in the packet. In this payload 212, a command 213 indicating that the packet is a command for confirming the availability, and a designated channel number 214 indicating a channel confirmed between the two are described. It should be noted that in the empty confirmation response packet, the confirmation status in the counterpart wireless device 2 with respect to the empty confirmation packet transmitted from the wireless communication device 1 is added in the payload 212.

  The output level control means 16C has a function for obtaining a channel status indicating the excess or deficiency of the number of usable channels obtained from the availability of each channel confirmed by the channel management means 16B, and an available channel or an unusable channel based on the channel status. And the function of instructing the wireless module 11 to update the output level table 13B. Further, it also has a function of instructing the wireless module 11 to notify the counterpart wireless device 2 of the output level change according to the change of the wireless output level.

[Operation of First Embodiment]
Next, the operation of the wireless communication apparatus according to the first embodiment of the present invention will be described with reference to FIG. 6 and FIG. FIG. 6 is a flowchart showing a wireless output level control process of the wireless communication apparatus according to the first embodiment of the present invention. FIG. 7 is an explanatory diagram illustrating determination criteria used for the wireless output level control operation of the wireless communication device according to the first embodiment of the present invention.

The module control unit 14 of the wireless module 11 performs, for example, a predetermined cycle by the output level control means 16C when data communication is performed with the counterpart wireless device 2 or when data communication is not performed. Thus, the wireless output level control process shown in FIG. 6 is performed based on the determination criteria of FIG.
Here, a case where determination is performed based on the number of usable channels will be described as an example, but the present invention is not limited to this, and the ratio of usable channels to the total number of channels may be used, or the number of unusable channels Alternatively, the ratio of unavailable channels to the total number of channels may be used.

First, the output level control means 16C initializes the output level of each channel to a predetermined value such as a maximum value by instructing the wireless module 11 to update the output level table 13B (step 300).
Next, the output level control means 16C refers to the channel table 13A of the wireless module 11 and counts the number of usable channels X confirmed by the channel management means 16B (step 301). The value is compared (step 302). The reference value is the number of usable channels that is the minimum required to obtain the desired communication quality.

Here, when the number X of usable channels is smaller than the reference value (step 302: NO), it is determined that the usable channels are insufficient as the channel status indicating the excess or shortage of usable channels (step 310).
When the usable channels are insufficient, the output level control means 16C checks whether or not the current output level is the maximum value for each unusable channel (step 311). If there is a channel whose output level is lower than the maximum value among the unusable channels (step 311: NO), the output level of these channels is increased by a predetermined amount (step 314), and the output level table 13B corresponding to this is increased. The wireless module 11 is instructed to update the wireless communication device 2 and to notify the counterpart wireless device 2 about the output level change of these channels, and the process returns to step 301.

When increasing / decreasing the output level of an arbitrary channel, as shown in FIG. 8, each output level can be divided in stages, and the actual output power corresponding to each output level stage can be set in advance. Good. As a result, when the output level is increased or decreased, the output level step may be shifted one step up or down, and a desired output bell can be easily specified for the wireless module 11.
At this time, as an output power difference between the output level stages, an arbitrary power width can be set according to the radio wave propagation characteristics, and the output level can be effectively increased or decreased according to switching of the output level stages.

On the other hand, when the output levels of all the unusable channels are the maximum values (step 311: YES), the number of usable channels X is compared with the lower limit value (step 312). The lower limit value is the minimum number of usable channels necessary for data communication.
Here, when the number of usable channels X is less than the lower limit (step 312: YES), it is determined that communication is not possible with the number of usable channels X, and communication incompatibility control is performed such as visual or audible display indicating that communication is not possible. (Step 313), the process returns to Step 301.
If the number of usable channels X is equal to or greater than the lower limit (step 312: NO), it is determined that communication is possible although the communication quality is low, and the process returns to step 301.

In step 302, if the usable channel number X is equal to or larger than the reference value (step 302: YES), the usable channel number X is compared with the upper limit value (step 303). The upper limit value is the upper limit number of usable channels necessary for obtaining desired communication quality.
Here, when the number X of usable channels is equal to or greater than the upper limit value (step 303: YES), it is determined that the number of usable channels is excessive as the channel status indicating the excessive or insufficient usable channels (step 320).

When the usable channels are excessive, the output level control means 16C determines whether or not the current output level is the minimum value for each usable channel (step 321). If there is a channel whose output level is greater than the minimum value among the usable channels (step 321: NO), the output level of these channels is reduced by a predetermined amount (step 322), and the output level table 13B corresponding to this is reduced. The wireless module 11 is instructed to update the wireless communication device 2 and to notify the counterpart wireless device 2 about the output level change of these channels, and the process returns to step 301.
On the other hand, if the output levels of all the available channels are minimum values (step 321: YES), there is no channel that reduces the output level, and the process returns to step 301.

  In step 303, if the number of available channels X is less than the upper limit value (step 303: NO), it is determined that the number of available channels is appropriate as the channel status indicating the excess or deficiency of available channels. (Step 330), the process returns to Step 301.

  As described above, in this embodiment, the channel management unit 16B confirms whether or not the channel can be used according to whether or not an error has occurred in packet transmission / reception in an arbitrary channel, and determines the usable channel obtained from the confirmation result. Since the wireless output level in the wireless transmission / reception unit 12 is adjusted by the output level control means based on the channel status indicating excess or deficiency, the number of usable channels can be increased or decreased, and an appropriate number corresponding to the desired communication quality Data communication can be performed using the channels.

As a result, when the number of usable channels is insufficient, the output level of the unusable channels is increased so that the channels with improved radio wave environment can be used. Thereby, the number of usable channels can be increased as a whole, and desired communication quality can be obtained.
In addition, when the number of usable channels is excessive, by reducing the output level of the usable channels, the channels cannot be used in channels in which the radio wave environment has deteriorated. Thereby, it is possible to reduce the transmission power corresponding to the desired communication quality as a whole, reduce the influence on other wireless communication, and share the communication band efficiently. Furthermore, the power consumption can be suppressed by reducing the wireless output level, and the operation time can be extended by suppressing the power consumption in a wireless communication terminal that operates with a secondary power source such as a battery.

[Second Embodiment]
Next, with reference to FIG. 9, the radio | wireless communication apparatus concerning the 2nd Embodiment of this invention is demonstrated. FIG. 9 is a sequence diagram illustrating a channel availability confirmation operation of the wireless communication device according to the second embodiment of the present invention.
In the present embodiment, a case will be described in detail where the channel availability confirmation is performed when data communication with the counterpart wireless device 2 is not being performed.

The wireless communication device 1 checks whether or not each channel can be used based on the sequence shown in FIG. 9 when no data communication is performed with the counterpart wireless device 2.
First, the channel management unit 16B selects one of the channels in a predetermined order (step 100), and outputs a channel confirmation request packet to the wireless module 11 in order to confirm the availability of the channel (step 101). ).

The module control unit 14 of the wireless module 11 receives the channel confirmation request packet from the host control unit 16 through the communication control unit 14A, and transmits the partner wireless communication from the wireless transmission / reception unit 12 via the wireless line 3 in any available channel. It transmits to the apparatus 2 (step 102).
The counterpart wireless device 2 returns a channel confirmation request response in response to the channel confirmation request packet (step 103), and temporarily selects the channel designated by the packet at the time of the next channel availability confirmation.

The channel management means 16B of the wireless communication apparatus 1 receives a channel confirmation request response via the communication control means 14A of the wireless module 11, and then sends an empty confirmation packet for confirming whether or not the designated channel is usable to the wireless module 11. On the other hand, the data is output (step 105).
The module control unit 14 of the wireless module 11 receives the empty confirmation packet from the host control unit 16 by the communication control unit 14A, and uses the channel specified by the previous channel confirmation request from the wireless transmission / reception unit 12 via the wireless line 3. Transmit to the counterpart wireless device 2 (step 106).

The counterpart wireless device 2 receives a vacant confirmation packet from the channel specified in the previous channel confirmation request, and wirelessly transmits a vacant confirmation response packet including the reception status of the vacant confirmation packet as a slave side confirmation status using the channel. It transmits to the communication apparatus 1 (step 107).
The module control unit 14 of the wireless communication device 1 receives the empty confirmation response packet from the counterpart wireless device 2 via the wireless transmission / reception unit 12 by the communication control unit 14A, and confirms the reception status of the packet and the packet on the master side. The situation is passed to the host controller 16 (step 108).

The channel management unit 16B of the host control unit 16 receives the slave side confirmation status and the host side confirmation status notified from the counterpart wireless device 2 from the wireless module 11, and confirms whether the channel can be used. In this case, since the slave side confirmation status and the host side confirmation status do not indicate that an error has occurred, it is determined that the channel is usable (step 110), and the wireless module 11 is allowed to use the channel. An instruction to update the table 13A is given (step 111).
If the slave side confirmation status or the host side confirmation status indicates that an error has occurred, it is determined that the channel is unusable (step 110), and the channel that disables the channel for the wireless module 11 is determined. An instruction to update the table 13A is given (step 111).

In this way, the channel management unit 16B of the host control unit 16 repeatedly executes steps 100 to 112 for each channel, thereby confirming whether each channel is available and updating the channel table 13A.
Thereafter, the channel management means 16B instructs to notify the counterpart wireless device 2 of the updated channel table 13A at a predetermined timing, for example, when the availability check for each channel is completed or periodically (step 120).

In response to this, the communication control unit 14A of the wireless module 11 updates the channel availability information in the channel table 13A of the module storage unit 13 to unavailable (step 112).
Further, the communication control unit 14A reads the packet including the entire contents of the channel table 13A from the module storage unit 13 instead of the transmission data, and transmits the packet including the entire contents of the channel table 13A from the wireless transmission / reception unit 12 via the wireless line 3 via any available channel. It transmits to the other party radio | wireless apparatus 2 (step 121).

The counterpart wireless device 2 updates the channel table in response to the notification from the wireless communication device 1 (step 122), and returns a table notification response (step 123).
The channel management means 16B of the wireless communication apparatus 1 receives the table notification response via the communication control means 14A of the wireless module 11 (step 124) and confirms the channel table update.
As a result, the contents of the channel table are synchronized between the wireless communication device 1 and the counterpart wireless device 2, and the unusable channel can be recognized between the two at the start of subsequent data communication.

  As described above, in this embodiment, the channel management unit 16B transmits / receives a predetermined confirmation packet to / from the counterpart wireless device 2 for each channel when no data communication is performed with the counterpart wireless device 2. Thus, the availability of each channel is confirmed, and the availability of these channels is set in the channel table 13A, so that the availability of the channels can be grasped before the start of data communication.

  Therefore, the wireless output level of each channel is set to an appropriate value by executing the wireless output control operation described in the first embodiment at the time of non-communication based on the confirmation result of such channel availability. Compared with the case where all channels are initialized to a predetermined wireless output level and data communication is started, desired communication quality can be obtained from the start of data communication, and there is no excess or deficiency. The channel can be used efficiently.

In this embodiment, the case has been described as an example in which the availability of each channel is confirmed when there is no data communication with the counterpart wireless device 2, but the channel availability confirmation operation is always performed. Instead of performing it, you may perform the usability confirmation operation with a certain interval. For example, the channel availability confirmation may be repeated for each channel, and then repeated at predetermined intervals, and the channel availability confirmation is longer than the frequency hopping interval used for data communication. May be repeated.
As a result, it is possible to reduce the processing load due to the channel availability check operation during non-communication, reduce the frequency of channel use, that is, traffic, and suppress the influence on other wireless devices that use the same communication band.

Further, in the present embodiment, when re-confirming the availability of an unusable channel, the case where the partner wireless device 2 is notified of the channel to be reconfirmed in advance is described as an example. The availability channel may be sequentially selected based on the order of frequency hopping channel selection used in the data communication.
In this case, the channel management means 16B of the host control unit 16 selects the channel selection order such as the channel selection order and the channel number order used for frequency hopping at the time of data communication, and the channel selection by confirming whether or not the channel can be used when not communicating. Notification is made to the counterpart wireless device 2 in order.

  This eliminates the need to notify the counterpart wireless device 2 each time which channel is to be confirmed when confirming whether or not each channel can be used, and the above-described steps 101 to 104 in FIG. 9 can be omitted. Accordingly, it is possible to reduce the processing load due to the channel availability confirmation operation when not communicating, to reduce the frequency of use of the channel, that is, traffic, and to suppress the influence on other wireless devices using the same communication band.

[Third Embodiment]
Next, with reference to FIG. 10, an operation of the wireless communication apparatus according to the third embodiment of the present invention will be described. FIG. 10 is a sequence diagram illustrating a data communication operation (at the time of a data communication error) of the wireless communication apparatus according to the third embodiment of the present invention. FIG. 11 is a sequence diagram showing channel availability confirmation (when available) of the wireless communication apparatus according to the third embodiment of the present invention.

  The wireless communication device 1 on the master side in the Bluetooth wireless communication system performs data communication based on the sequence shown in FIG. 10 when performing data communication with the counterpart wireless device 2 on the slave side. At this time, it is assumed that various arrangements such as channel selection order in frequency hopping have already been performed between the two at the start of data communication.

The host control unit 16 of the wireless communication apparatus 1 outputs a data transmission instruction including a transmission packet of desired data to the wireless module 11 by the data communication unit 16A (step 130).
In response to this, the module control unit 14 of the wireless module 11 selects the next channel in the usable state based on a predetermined channel selection order by referring to the channel table 13A of the module storage unit 13 by the communication control unit 14A. Then, the transmission packet of the data transmission instruction from the host control unit 16 is transmitted from the wireless transmission / reception unit 12 to the counterpart wireless device 2 via the wireless line 3 (step 131).

The counterpart wireless device 2 should select a channel based on the order of channel selection in frequency hopping decided with the wireless communication device 1 at the start of wireless reception, receive a packet from the wireless communication device 1, receive data, and transmit A packet including the data and the slave-side reception status for the data transmitted from the wireless communication device 1 is transmitted to the wireless communication device 1 using the channel (step 132).
The module control unit 14 of the wireless communication device 1 receives the packet from the counterpart wireless device 2 via the wireless transmission / reception unit 12 by the communication control unit 14A, and the host control unit 16 indicates the reception status of the packet and the packet on the master side. (Step 133).

  The data communication unit 16 </ b> A of the host control unit 16 receives data from the packet from the wireless module 11. Further, the channel management unit 16B receives the slave side reception status and the host side reception status notified from the counterpart wireless device 2 from the radio module 11, and confirms whether or not the channel can be used. In this case, since the reception status on the slave side and the reception status on the host side do not indicate that an error has occurred, it is determined that the channel is usable.

In this way, the module control unit 14 of the wireless communication device 1 sequentially selects channels based on the channel selection order in frequency hopping decided with the counterpart wireless device 2 at the start of wireless communication by the communication control unit 14A. Packets are exchanged with the counterpart wireless device 2 (steps 135 to 138).
Here, for example, when the packet transmitted from the wireless communication device 1 cannot be received by the counterpart wireless device 2 (step 136), the slave-side reception status from the counterpart wireless device 2 indicates that an error has occurred.

  When the slave side reception status or the master side reception status indicates that an error has occurred, the channel management means 16B of the wireless communication device 1 determines that the channel is unusable (step 140), and sends the channel to the wireless module 11 Is instructed to update the channel table 13A that cannot be used (step 141), and a notification to the counterpart wireless device 2 of the updated channel table 13A is instructed (step 150).

In response to this, the communication control unit 14A of the wireless module 11 updates the channel availability information in the channel table 13A of the module storage unit 13 to unavailable (step 142).
Further, the communication control unit 14A reads out the packet including the entire contents of the channel table 13A from the module storage unit 13 instead of the transmission data, for example, the channel selected by the next frequency hopping from the wireless transmission / reception unit 12 to the wireless line 3 To the counterpart wireless device 2 (step 151).

The counterpart wireless device 2 updates the channel table in response to the notification from the wireless communication device 1 (step 152), and returns a table notification response (step 153).
The channel management means 16B of the wireless communication apparatus 1 receives the table notification response via the communication control means 14A of the wireless module 11 (step 154), and confirms the channel table update.
In this way, the host control unit 16 of the wireless communication device 1 completes both channel table update processing for the disabled channel by the channel management unit 16B, and then uses the data communication unit 16A to transmit the next data. Transmission is resumed (steps 130 to 133). As a result, the disabled channel is not selected by frequency hopping.

Thereafter, the wireless communication device 1 reconfirms the availability of the unavailable channel based on the sequence shown in FIG.
At this time, in the same manner as in FIG. 10 described above, the channel management means 16B performs the data communication (steps 130 to 133), and the channel table 13A of the wireless module 11 at a predetermined cycle as in steps 100 to 108 of FIG. , A channel that is set to be unusable is selected, and a channel confirmation request packet or a vacancy confirmation packet is exchanged with the counterpart wireless device 2 via the wireless module 11, thereby Confirm the availability of.

  Thereafter, if necessary, the channel table 13A is updated based on the availability as in the same manner as in steps 110 to 112 in FIG. 9, and further updated in the same manner as in steps 120 to 124 in FIG. To the counterpart wireless device 2 and update both channel tables. Then, the original data communication (steps 130 to 133) is resumed.

  Note that the channel management means 16B cannot use the channel when the confirmation status of the slave side or the confirmation status of the host side indicates that an error has occurred as a result of exchanging the empty confirmation packet with the counterpart wireless device 2. (Step 110). At this time, since it is not necessary to update the channel table 13A, steps 111, 112, and 120 to 124 in FIG. 11 are not executed, and the original data communication (steps 130 to 133) is resumed.

  As described above, in this embodiment, the channel management unit 16B of the host control unit 16 reconfirms the use of the channel during data communication for the channel set as unavailable in the channel table 13A and uses it. When it is confirmed that the channel is available, the channel table 13A is updated to indicate that the channel is usable, so that the availability of the channel can be grasped during data communication.

  Therefore, the wireless output level of each channel is always set to an appropriate value by executing the wireless output control operation described in the first embodiment during wireless communication based on the confirmation result of the channel availability. Even if the radio wave environment changes during data communication, it is possible to obtain a desired communication quality corresponding to the change, and it is possible to efficiently use channels without excess or deficiency.

In this embodiment, a case has been described as an example in which reconfirmation of channel availability is performed according to the occurrence of a periodic or unusable channel. However, the present invention is not limited to this, and communication required You may make it carry out at another timing according to quality.
For example, the re-confirmation of availability can be started immediately in response to the occurrence of an unusable channel, and the availability of the channel can be confirmed in a shorter period, and high communication quality can be maintained. At this time, the reconfirmation cycle for the same channel may be arbitrarily selected according to the communication quality required for the data communication.
Alternatively, re-confirmation of availability may be started after a certain period of time so that a change in the radio wave condition appears after the occurrence of an unusable channel, and re-confirmation can be performed more efficiently.

Further, as a method for selecting a channel to be reconfirmed, an unusable channel may be sequentially selected from among the channels based on the frequency hopping channel selection order used for data communication with the counterpart wireless device 2.
As a result, the notification of the reconfirmation channel to the counterpart wireless device 2 that is required when reconfirming the availability of the channel during the data communication can be omitted, the delay of the data communication due to the channel availability reconfirmation operation, The effect of interruptions can be reduced.

At this time, the channel management means 16B counts the number of frequency hoppings after reconfirmation of channel availability and the number of laps in a series of channel selection order, or directly measures the elapsed time since reconfirmation of channel availability. To check whether the frequency of the channel availability reconfirmation operation is equal to or higher than a predetermined interval, and if the predetermined interval is not obtained, execute the availability reconfirmation in response to the notification of the unavailable channel from the communication control unit 14A. Instead, the communication control unit 14A may be instructed to skip to the next available channel and continue the data communication.
Thereby, even when unavailable channels are continuous or concentrated according to the channel selection order of frequency hopping, it is possible to reduce the influence of data communication delay or interruption caused by the channel availability reconfirmation operation.

[Extended embodiment]
In each of the above embodiments, the case where the wireless communication device 1 is the master side has been described as an example. However, in the Bluetooth wireless communication method, the same device also has a slave-side function. In each embodiment, a function for processing a channel confirmation request packet and a vacancy confirmation packet from the master side is required as a channel availability confirmation function on the slave side. For such a function, the channel of the host control unit 16 What is necessary is just to perform by the management means 16B. As for the slave-side wireless output level control function, the same function may be provided by the output level control means 16C of the host control unit 16 that provides the master-side wireless output level control function described above.

  In the above description, the case where the channel management unit 16B and the output level control unit 16C are provided in the host control unit 16 has been described as an example. However, any or all of these units may be realized by the module control unit 14, It can be implemented in the wireless module as one of the adaptive frequency hopping functions of the Bluetooth wireless communication system. Thereby, the processing in the host control unit 16 can be greatly reduced, and an inexpensive wireless communication apparatus as a whole can be realized.

  In the above description, the case where the wireless output level control operation in the output level control means 16C is periodically executed has been described. However, the present invention is not limited to this. For example, it is executed according to a change in channel availability. It may be.

Further, the change of the output level may be notified to the counterpart wireless device 2, and the counterpart communication device 2 adjusts the radio output level of each channel according to the content thereof, and the adjustment is performed only on the master side. A greater effect can be obtained in comparison.
In this case, only the output level related to the changed channel may be notified, or the output level related to all channels, for example, the entire output level table 13B may be notified to the counterpart wireless device 2 in the same manner as the channel table 13A. Further, an output level column may be provided in the channel table 13A and notified to the counterpart wireless device 2 as partial data of the channel table 13A.

  In each of the above embodiments, Bluetooth has been described as an example. However, the frequency hopping / spread spectrum modulation method is also used in other wireless interfaces such as a wireless LAN (IEEE802.11). Each embodiment can be applied in the same manner as described above, and the same effects can be obtained.

It is a block diagram which shows the structure of the radio | wireless communication apparatus concerning the 1st Embodiment of this invention. It is a structural example of a channel table. It is an example of a structure of an output level table. It is an example of a structure of an empty channel confirmation request packet. It is a structural example of an empty confirmation packet. It is a flowchart which shows the radio | wireless output level control process of the radio | wireless communication apparatus concerning the 1st Embodiment of this invention. It is explanatory drawing which shows the criterion used for the radio | wireless output level control operation | movement of the radio | wireless communication apparatus concerning the 1st Embodiment of this invention. It is explanatory drawing which shows an output level step. It is a sequence diagram which shows the channel use availability confirmation operation | movement of the radio | wireless communication apparatus concerning the 2nd Embodiment of this invention. It is a sequence diagram which shows the data communication operation | movement (at the time of a data communication error) of the radio | wireless communication apparatus concerning the 3rd Embodiment of this invention. It is a sequence diagram which shows the channel availability confirmation (at the time of use) of the radio | wireless communication apparatus concerning the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wireless communication apparatus, 11 ... Wireless module, 12 ... Wireless transmission / reception part, 13 ... Module memory | storage part, 13A ... Channel table, 13B ... Output level table, 14 ... Module control part, 14A ... Communication control means, 15 ... Functional processing 16, host control unit, 16 A, data communication means, 16 B, channel management means, 16 C, output level control means, 2, partner wireless device, 3, wireless line.

Claims (2)

By transmitting and receiving a desired packet using a channel sequentially connected in accordance with a predetermined channel selection order from a plurality of channels having different carrier frequencies by being connected to the counterpart radio device via a radio line, A wireless communication device that performs data communication and disables use of the channel when an error occurs in packet transmission / reception in an arbitrary channel,
A storage unit for storing a channel table for managing availability of each channel and an output level table for managing a radio output level of each channel;
A radio transceiver for receiving a packet from the counterpart wireless device using the selected channel and transmitting the packet to the counterpart wireless device at the radio output level of the channel set in the output level table;
Communication control means for sequentially transmitting and receiving packets by the wireless transmission / reception unit by sequentially selecting a channel indicating availability from the channel table according to the channel selection order during the data communication;
Based on the confirmation status indicating the packet reception status in any channel notified from the counterpart wireless device, the presence or absence of an error in packet transmission / reception in the channel is confirmed, and the availability of the channel is determined according to the confirmation result Channel management means set in the channel table;
When the number of usable channels used for the data communication obtained from the channel table is smaller than a predetermined reference value, it is determined that the number of usable channels is insufficient, and the number of usable channels is equal to or greater than the reference value. Te, and when it is more than a predetermined upper limit value is determined as the number of available channels is excessive, the output level table to adjust the radio output level of the channel based on the excessive lack of these available channels Output level control means for setting , and
The power level control means increases the radio power level of the unusable channel when the channel status indicates an insufficient number of usable channels, and when the channel status indicates an excessive number of usable channels, the use is possible. A wireless communication apparatus characterized by reducing a wireless output level of a channel . The wireless communication device according to claim 1,
The channel management means notifies the partner wireless device of a channel to be checked when the data communication is not performed with the partner wireless device, and then selects the channel and selects the partner. A wireless communication device, wherein a confirmation packet is transmitted to and received from a wireless device, and whether or not the channel is usable is confirmed according to whether or not an error has occurred.

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