JP2006287428A - Radio communication apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently utilize a channel to be used for frequency hopping by enabling to avoid the integrated generation of unusable channels in an initial stage of start of communication. <P>SOLUTION: During non-communication period when data communication is not performed with an opposite party radio device 2, a channel management means 16B of a radio communication apparatus 1 confirms propriety of usage of each channel for each channel, and sets the propriety of usage of these channels in a channel table 13A. <P>COPYRIGHT: (C)2007,JPO&INPIT

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 a packet transmission / reception error occurs in an arbitrary channel due to a radio wave transmitted from another device, adaptive frequency hopping (hereinafter referred to as AFH: Adaptive) which disables the use of that channel. Frequency Hopping) technology is 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, in such a conventional technique, since data communication is started on the premise that all channels are usable, depending on the radio wave environment, unusable channels are concentrated at the beginning of communication, and communication quality deteriorates. There was a problem.
The present invention has been made to solve such problems, and an object of the present invention is to provide a wireless communication apparatus and method capable of avoiding concentration of unusable channels at the beginning of communication.

  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 counterpart wireless device by transmitting and receiving a desired packet using any given channel, a storage unit that stores a channel table that manages the availability of each channel, and data communication Each time, when there is no data communication between the communication control means for transmitting and receiving packets by sequentially selecting a channel indicating the availability from the channel table according to the channel selection order and the partner wireless device for each channel A channel tube that checks the availability of channels and sets the availability of these channels in the channel table. And a means.

  At this time, when confirming whether or not the channel can be used by the channel management means, after notifying the partner wireless device of the channel to be confirmed, the channel is selected and the confirmation packet is transmitted to and received from the partner wireless device. Whether or not the channel can be used may be confirmed according to whether or not the error has occurred.

  The channel management means may notify the counterpart wireless device of the contents of the channel table when starting data communication.

  Also, when the channel management means checks whether or not the channel can be used, the channel is selected from each channel in a predetermined order, and a confirmation packet is transmitted / received to / from the counterpart wireless device. It may be possible to confirm whether it is possible.

  Also, the wireless communication method according to the present invention is an arbitrary channel that is sequentially selected from a plurality of channels having different carrier frequencies according to a predetermined channel selection order by a wireless communication device connected to a counterpart wireless device via a wireless line. Is a wireless communication method for performing data communication with a counterpart wireless device by transmitting and receiving a desired packet using a storage step for storing a channel table for managing the availability of each channel in a storage unit; The communication control step for sequentially transmitting and receiving packets by sequentially selecting channels indicating availability from the channel table according to the channel selection order, and whether or not each channel can be used when no data communication is performed between the partner wireless devices And set the channel table to determine whether or not these channels can be used. Tsu and a flop.

  At this time, in the channel management step, when confirming whether or not the channel can be used, after notifying the partner wireless device of the channel to be confirmed, the channel is selected and a confirmation packet is transmitted to and received from the partner wireless device. Whether or not the channel can be used may be confirmed according to whether or not the error has occurred.

  In the channel management step, the contents of the channel table may be notified to the counterpart wireless device when starting data communication.

  Also, when confirming the availability of a channel in the channel management step, the channel is selected from each channel in a predetermined order, and a confirmation packet is transmitted / received to / from the counterpart wireless device. It may be possible to confirm whether it is possible.

According to the present invention, the channel management means transmits and receives a predetermined confirmation packet to and from the partner wireless device for each channel when data communication is not performed with the partner wireless device and communication is not performed. Since the availability is confirmed and the availability of these channels is set in the channel table, the unavailable channel can be grasped at the start of data communication.
Therefore, compared to the case where data communication is started on the premise that all channels can be used as before, even when the radio wave environment is bad, unusable channels are not concentrated at the beginning of communication. Therefore, it is possible to avoid deterioration in communication quality due to concentration of unusable channels.

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.
This 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 wireless communication device 1 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. The availability of channels is confirmed, and the availability of these channels is set in a channel table that manages the availability of each channel.

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. have. 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. As main processing information stored in the module storage unit 13, there is a channel table 13A.
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.
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. And a function of instructing the wireless transmission / reception unit 12 by sequentially selecting one of the channels based on the channel selection order determined at the start of data communication. 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. Update function.

  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 and a channel management means 16B.

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 means 16B determines whether or not each channel can be used according to the communication status from the wireless module 11, and if necessary, instructs the wireless module 11 to update the channel table 13A, and the partner wireless device. The function of instructing the wireless module 11 to reconfirm whether the wireless module 11 can be used with the counterpart wireless device 2 when no data communication is performed and the wireless module 11 according to the update of the channel table 13A. And a function for instructing the partner wireless device 2 to update the notification 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. 3 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 shown in FIG. 3 includes an access code 200 including information on synchronization and options, a header 201 for storing 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. 4 is provided with an access code 210 including information on synchronization and options, a header 211 for storing the 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.

[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. FIG. 5 is a sequence diagram showing a channel confirmation operation of the wireless communication apparatus according to the first embodiment of the present invention.

The wireless communication device 1 confirms whether or not each channel can be used based on the sequence shown in FIG. 5 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 means 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 or not 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 is determined to be unusable for the wireless module 11. 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 counterpart wireless device 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 and receives a predetermined confirmation packet to and from the partner wireless device 2 for each channel when no data communication is performed with the partner 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 unavailable channel can be grasped at the start of data communication.
Therefore, compared to the case where data communication is started on the premise that all channels can be used as before, even when the radio wave environment is bad, unusable channels are not concentrated at the beginning of communication. Therefore, it is possible to avoid deterioration in communication quality due to concentration of unusable channels.

[Second Embodiment]
Next, a radio communication apparatus according to the second embodiment of the present invention will be described.
In the first embodiment described above, the host control unit 16 of the wireless communication apparatus 1 uses the channel management unit 16B to check the contents of the channel table 13A indicating whether each channel is available periodically or not. A case has been described in which notification is sent to the counterpart wireless device 2 when the confirmation is completed.

In the present embodiment, the channel table 13A is notified to the partner wireless device 2 when data communication with the partner wireless device 2 is started. In this case, the processing of steps 120 to 124 described above may be executed at the start of data communication.
Thereby, the frequency | count of notifying the channel table 13A to the other party radio | wireless apparatus 2 can be minimized, and the processing burden regarding the notification process of the channel table 13A can be reduced. Note that the configuration of the wireless communication apparatus 1 is the same as that of FIG. 1 described above, and a detailed description thereof is omitted here.

[Third Embodiment]
Next, a radio communication apparatus according to the second embodiment of the present invention will be described.
In the first embodiment described above, the host control unit 16 of the wireless communication device 1 has been described as an example of the case where the channel management unit 16B notifies the partner wireless device 2 about the channel for which the availability is confirmed each time. .
In the present embodiment, a case will be described in which the availability of channels is confirmed in a predetermined channel selection order. Note that the configuration of the wireless communication apparatus 1 is the same as that of FIG. 1 described above, and a detailed description thereof is omitted here.

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 about which channel is to be confirmed each time when confirming whether or not each channel can be used, and the above-described steps 101 to 104 in FIG. 5 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.

[Extended embodiment]
In each of the above embodiments, the case where the availability of each channel is confirmed when data communication with the counterpart wireless device 2 is not performed has been described as an example. However, 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.

  In the above description, 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 (step 102) and a vacancy confirmation packet (step 106) from the master side is required as a function on the slave side. The channel management means 16B of the unit 16 may be used.

  In the above description, the case where the channel management unit 16B is provided in the host control unit 16 has been described as an example. However, the channel management unit 16B may be realized by the module control unit 14, and an adaptive frequency hopping function of the Bluetooth wireless communication system may be used. One of them can be mounted in a wireless module. 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 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 empty channel confirmation request packet. It is a structural example of an empty confirmation packet. It is a sequence diagram which shows the channel use availability confirmation operation | movement of the radio | wireless communication apparatus concerning the 1st 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, 14 ... Module control part, 14A ... Communication control means, 15 ... Function processing part, 16 ... Host control 16A ... data communication means, 16B ... channel management means, 2 ... counterpart wireless device, 3 ... wireless line.

Claims (8)

The partner wireless device is connected to the partner wireless device via a wireless line and transmits / receives a desired packet using an arbitrary channel sequentially selected according to a predetermined channel selection order from a plurality of channels having different carrier frequencies. A wireless communication device that performs data communication with
A storage unit for storing a channel table for managing the availability of each channel;
Communication control means for sequentially transmitting and receiving packets by sequentially selecting a channel indicating availability from the channel table according to the channel selection order during the data communication;
Channel management means for confirming the availability of each channel for each channel and setting the availability of these channels in the channel table when the data communication is not performed with the counterpart wireless device; A wireless communication apparatus comprising: The wireless communication device according to claim 1,
The channel management means, when confirming the availability of the channel, notifies the partner wireless device of the channel to be confirmed, then selects the channel and transmits / receives the confirmation packet to / from the partner wireless device. And confirming whether or not the channel can be used according to whether or not an error has occurred. The wireless communication device according to claim 1,
The wireless communication device, wherein the channel management means notifies the counterpart wireless device of the contents of the channel table when starting the data communication. The wireless communication device according to claim 1,
The channel management means, when confirming the availability of the channel, selects a channel from each channel in a predetermined order and transmits / receives the confirmation packet to / from the counterpart wireless device, and depending on whether or not an error has occurred, A wireless communication apparatus that checks whether or not a channel can be used. By transmitting / receiving a desired packet using an arbitrary channel sequentially selected according to a predetermined channel selection order from a plurality of channels having different carrier frequencies by a wireless communication device connected to a partner wireless device via a wireless line A line communication method for performing data communication with the counterpart wireless device,
A storage step of storing a channel table for managing availability of each channel in a storage unit;
A communication control step of transmitting and receiving packets by sequentially selecting channels indicating availability from the channel table according to the channel selection order during the data communication;
A channel management step of confirming availability of each channel when the data communication is not performed with the counterpart wireless device and setting the availability of these channels in the channel table. A wireless communication method. The wireless communication method according to claim 5, wherein
The channel management step, when confirming the availability of the channel, notifies the partner wireless device of the channel to be confirmed, then selects the channel and performs transmission / reception of a confirmation packet with the partner wireless device. A wireless communication method characterized by confirming whether or not the channel can be used according to whether or not an error has occurred. The wireless communication method according to claim 5, wherein
The channel management step of notifying the content of the channel table to the counterpart wireless device when starting the data communication. The wireless communication method according to claim 5, wherein
In the channel management step, when confirming whether or not the channel is usable, the channel is selected from each channel in a predetermined order, and the confirmation packet is transmitted / received to / from the counterpart wireless device. A wireless communication method characterized by confirming whether or not a channel can be used.

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