JP2010278764A - Wireless communication apparatus and band controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication apparatus, capable of preventing interference between communication of a WLAN apparatus and communication of a BT apparatus in the self apparatus, while preventing interference between communication of the other wireless LAN apparatus and communication of the BT apparatus, and further reducing the provability of shortage of a channel which can be used by the BT apparatus. <P>SOLUTION: A wireless communication apparatus has a WLAN apparatus 1, a BT apparatus 2, and a wireless channel controller 3 that decides a channel which can be used by the BT apparatus 2 based on channel information generated by the WLAN apparatus 1. The BT apparatus 2 notifies the wireless channel controller 3 of an insufficient band or a required band, when the deterioration of communication quality is to be detected. The wireless channel controller 3 instructs a change of the channel to be used or a temporary stop of communication to the WLAN apparatus 1, when receiving a notification of the shortfall band or required band from the BT apparatus 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus and a bandwidth control method that are compatible with two different wireless communication systems and that can simultaneously execute communication in the respective systems.

  In recent years, various wireless devices (wireless communication devices) using the 2.4 GHz band of an ISM (Industry Science Medical) band have been actively developed. Wireless communication using the 2.4 GHz band includes wireless LAN (IEEE802.11b / g / n), Bluetooth (Bluetooth (registered trademark)), and the like. In addition, a composite device including a plurality of these wireless communication devices has been developed. For example, a configuration in which a portable wireless terminal that performs voice communication by connecting to a wireless LAN access point performs Bluetooth communication with a wireless headset worn by the user when providing a hands-free call function to the user is considered. It is done. In addition, in Bluetooth SIG (Special Interest Group), a system using Bluetooth-compatible devices and wireless LAN-compatible devices in combination, such as Bluetooth over WLAN as an alternative PHY and MAC, is also being studied.

  Here, in a wireless communication device using IEEE802.11b / g / n (hereinafter referred to as a WLAN device), in consideration of noise resistance, direct spread spectrum spread (Direct Sequence Spread Spectrum: DSSS) And OFDM (Orthogonal Frequency Division Multiplexing) technology. Further, in this WLAN device, communication is performed using one selected from 14 channels defined in the 2.4 GHz band ISM band in a fixed manner.

  In addition, in the WLAN device, in consideration of interoperability with other networks or other systems, each wireless terminal carrier senses the wireless channel prior to wireless packet transmission and confirms that the channel is in use (channel busy). In this case, the wireless access method CSMA / CA (Carrier Sense Multiplex) is used to transmit a wireless packet after a channel unused (channel idle) time and a back-off time determined in advance for each frame type have elapsed. Access with Collision Avoidance) is mainly introduced.

  On the other hand, in order to improve noise resistance, a wireless communication device compatible with Bluetooth (hereinafter referred to as a BT device) also employs a frequency hopping spread spectrum (FHSS) technique. In this FHSS technology, one FH channel is selected from 79 frequency channels (hereinafter referred to as FH channels) having a width of 1 MHz determined in a frequency band from 2.40 GHz to 2.48 GHz, and this is selected as time. Communicate while switching over time. More specifically, in this FHSS system, FH channel selection is repeatedly performed at a constant time interval (for example, 625 μs) based on a predetermined pseudo-random algorithm, and communication is performed by assigning one packet data to one FH channel. .

  Each channel used by the WLAN device has an occupied frequency bandwidth (22 MHz) corresponding to about 20 FH channels used by the BT device, and an interval between adjacent channels is 5 MHz. Further, the 14 channels used by the WLAN device are assigned with a center frequency between 2.412 GHz and 2.484 GHz, and occupy 2.401 GHz to 2.495 GHz.

  Therefore, if a BT device and a WLAN device that communicate using the same 2.4 GHz band are present in each other's communication area, radio waves transmitted from each other interfere with each other and interfere with each other's communication. In particular, in a composite device including a BT device and a WLAN device, and a system using both of them, some measure for preventing deterioration in communication quality due to this mutual interference is essential. An example of a technique for preventing the deterioration of communication quality by avoiding the occurrence of mutual interference in such a composite apparatus is described in Patent Document 1 below.

  The composite wireless device described in Patent Literature 1 below includes a WLAN device, a BT device, and a wireless channel control unit, and the wireless channel control unit acquires information on a channel in use from the WLAN device and uses the channel in use of the WLAN device. The BT apparatus is controlled so as to perform frequency hopping between channels other than the band occupied by (the FH channel for Bluetooth communication). At this time, if the BT device performs transmission on the FH channel close to the channel used by the WLAN device, an erroneous determination may occur due to carrier sense by the WLAN device, and the throughput may be reduced. The radio channel controller controls the BT device. Note that the radio channel control unit controls the BT device in consideration of not only the WLAN devices constituting the composite radio device but also the channels used by other neighboring WLAN devices. Specifically, first, information on the channels used by the WLAN devices constituting the composite wireless device and the channels used by other WLAN devices is used, and it is also considered that erroneous determination may occur in carrier sense. Thus, each FH channel is classified into a false detection danger channel, an unusable channel, and another channel (usable channel). If the number of usable channels is equal to or greater than the required number (the number of channels required for the frequency hopping operation), control is performed so that frequency hopping is performed using only the usable channels. If not, control is performed so that frequency hopping is performed using all available channels, as well as a shortage of FH channels selected from unavailable channels or more (semi-usable channels). .

JP 2008-172556 A

  In the composite wireless device described in Patent Document 1, when there are a large number of other neighboring WLAN devices, the shortage is made unusable when the number of FH channels classified as usable channels is less than the required number. The selected FH channels are selected in the order of channels with less interference. However, when the number of FH channels that are insufficient is large, the communication of the BT device gives a large interference to the WLAN device, and the resistance against the interference wave from the WLAN device in the communication of the BT device also deteriorates. There was a problem that it would.

  The present invention has been made in view of the above, and even when there are many other WLAN devices in the vicinity, the communication of the WLAN device in the own device and the communication of the BT device become interference with each other. In addition, the communication of another WLAN device and the communication of the BT device are prevented from interfering with each other, and the good channel (the channel that can be used by the BT device) described in Patent Document 1 is provided. It is an object of the present invention to obtain a radio communication apparatus and a bandwidth control method that can reduce the probability of shortage.

  In order to solve the above-described problems and achieve the object, the wireless communication device according to the present invention performs an operation in accordance with the wireless LAN standard, and when the channel scan is executed, the device itself and other communication devices around it Based on the channel information generated by the WLAN device that generates information on the channels that are used, the BT device that performs operations according to the Bluetooth standard, and the channel information generated by the WLAN device, the channels that can be used by the BT device are determined. A radio channel control unit to determine, and the BT device performs frequency hopping communication according to a determination result in the radio channel control unit, and when a deterioration in communication quality is detected, a shortage band or a necessary band To the radio channel control unit, and the radio channel control unit notifies the shortage band or the necessary band from the BT device. If the received, it compared the WLAN device, characterized by instructing the temporary suspension of the communication in change of the used channel, or the channel used.

  According to the present invention, when the communication quality in the BT device deteriorates and the bandwidth becomes insufficient, the WLAN device changes the WLAN channel to be used, so even in a situation where there are a plurality of other WLAN devices in the vicinity. As a result, it is possible to avoid the occurrence of erroneous carrier sense detection in the WLAN device and to secure the necessary number of channels for communication in the BT device.

FIG. 1 is a diagram illustrating a configuration example of a first embodiment of a wireless communication apparatus according to the present invention. FIG. 2 is a diagram illustrating a correspondence relationship between channels that can be used by the WLAN device and channels that can be used by the BT device. FIG. 3 is a diagram for explaining the operation of the wireless communication apparatus according to the first embodiment. FIG. 4 is a diagram for explaining the operation of the wireless communication apparatus according to the first embodiment. FIG. 5 is a diagram illustrating an example of used channel information and channel communication quality information. FIG. 6 is a diagram illustrating an example of a selection result of usable FH channels. FIG. 7 is a diagram illustrating an example of a selection result of usable FH channels. FIG. 8 is a diagram showing the positional relationship of communication WLAN channels. FIG. 9 is a diagram illustrating an example of used channel information and channel communication quality information. FIG. 10 is a diagram illustrating a modification of the wireless communication apparatus according to the first embodiment. FIG. 11 is a diagram illustrating a configuration example of a wireless communication apparatus according to the second embodiment. FIG. 12 is a diagram for explaining the operation of the wireless communication apparatus according to the second embodiment. FIG. 13 is a diagram for explaining the operation of the wireless communication apparatus according to the second embodiment. FIG. 14 is a diagram for explaining the operation of the wireless communication apparatus according to the second embodiment. FIG. 15 is a diagram illustrating an example of a selection result of usable FH channels.

  Embodiments of a wireless communication apparatus and a bandwidth control method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of a first embodiment of a wireless communication apparatus according to the present invention. This wireless communication device is used by the WLAN device 1 which is a communication device compatible with the wireless LAN (IEEE802.11b / g / n) standard, the BT device 2 which is a communication device compatible with the Bluetooth standard, and the WLAN device 1. A wireless channel control unit 3 that controls a wireless communication channel and a wireless communication channel used by the BT device 2, and the WLAN device 1 and the BT device 2 perform different types of communication according to instructions from the wireless channel control unit 3. Do it in parallel. FIG. 2 is a diagram showing a correspondence relationship between channels that can be used by the WLAN device 1 and channels that can be used by the BT device 2.

  As shown in FIG. 2, according to the IEEE802.11b / g / n standard that the WLAN device 1 supports, 14 frequency channels (indicated as “WLAN Channel” shown in the figure) in a 2.4 GHz frequency band at 5 MHz intervals. The WLAN device 1 selectively uses one or more arbitrary WLAN channels among these 14 WLAN channels. As already described, the occupied frequency bandwidth per channel is 22 MHz (see FIG. 2). The configuration of the WLAN device 1 will be described below.

  The WLAN device 1 shown in FIG. 1 includes a WLAN radio unit 11, a WLAN communication control unit 13, a host interface unit (not shown) for connecting to a terminal or a network, and the like.

  The WLAN radio unit 11 includes a carrier sense unit 12, an antenna (not shown), a transmission / reception signal amplification unit, a filter, a modulation / demodulation processing unit, a PLL (Phase Locked Loop) synthesizer, a baseband processing unit, and the like. . The carrier sense unit 12 performs carrier sense before starting communication, and confirms the state of the WLAN channel (communication WLAN channel) assigned for communication of the WLAN terminal 1. For example, when it is detected that the reception level of the WLAN channel is equal to or less than a predetermined time of −76 dBm, a transmission OK signal indicating that the communication WLAN channel is not used and can be used is transmitted to the WLAN communication control unit. 13 to send. The WLAN device 1 has two carrier sense levels for a radio frame of the same standard as that supported by the WLAN device 1 and a carrier sense level for a frame or interference from another system corresponding to a different standard. You may make it comprise so that carrier sense may be performed using properly.

  The WLAN communication control unit 13 includes an access control unit 14, a terminal management unit, a concealment processing unit, and a framer that are not shown. In addition to CSMA / CA, the access control unit 14 implements PCF (Point Coordination Function), EDCA (Enhanced Distributed Channel Access), HCCA (Hybrid Coordination Function (HCF) Controlled Channel Access), etc. Use properly for each.

  Further, in the Bluetooth standard that the BT device 2 supports, as shown in FIG. 2, the frequency band of 2.4 GHz band is divided into 79 frequency channels (corresponding to “FH Channel” shown in the figure). , Hereinafter referred to as FH channel). The BT device 2 basically performs communication by switching the frequency channel used in a time division every time slot (625 μs) according to a hopping pattern defined in advance. The configuration of the BT device 2 will be described below.

  The BT device 2 shown in FIG. 1 includes a BT radio unit 21, a BT communication control unit 22, an interface unit (not shown) with a host controller, and the like.

  Further, in the BT device 2, the BT radio unit 21 includes an antenna, an RF unit, a baseband processing unit, and the like that are not shown.

  The BT communication control unit 22 includes a frequency hopping channel determination unit 23, a link management unit 24, an access control unit not shown, and the like.

  The frequency hopping channel determination unit 23 determines a channel to be used in frequency hopping communication based on usable FH channel information (details will be described later) notified from the radio channel control unit 3. The link management unit 24 manages a communication link with another BT apparatus that is a communication partner, and includes a bit error rate, a packet error rate, RSSI (received power level), and SINR (Signal to Interference plus Noise Ratio). Are measured to determine whether or not the communication of the BT device 2 satisfies a desired communication quality, and the measurement result is notified to the radio channel control unit 3 as “communication quality information”.

  As described above, in the radio communication apparatus according to the present embodiment, the BT apparatus 2 determines the FH channel to be actually used by the frequency hopping channel determination unit 23 based on the usable FH channel information obtained from the radio channel control unit 3. To do. In addition, information indicating the communication quality of the BT device 2 (communication quality information) and information (band request information) for requesting allocation of a new band when the communication quality deteriorates and the band becomes insufficient are transmitted to the link management unit. 24 notifies the radio channel controller 3.

  The radio channel control unit 3 includes a use channel management unit 31 that manages each use channel in the WLAN device 1 and the BT device 2, and a communication quality management unit 32 that manages each communication quality in the WLAN device 1 and the BT device 2. And a QoS management unit 33 that manages the QoS of the entire wireless communication apparatus.

  Next, the overall operation of the wireless communication apparatus according to the present embodiment will be described. Here, an explanation will be made mainly on the operation (interference reduction method) for reducing the mutual interference between the communication of the WLAN device 1 and the communication of the BT device 2, which is a characteristic operation, and the operation related thereto, The description of the general operation of the wireless communication apparatus will be minimized. As an example, the operation in the environment shown in FIGS. 3 and 4 will be described.

  3 and 4 are diagrams for explaining the operation of the wireless communication apparatus according to the first embodiment. In FIG. 3, the portable terminal corresponds to the wireless communication apparatus of the present embodiment, and communicates with a WLAN access point (WLAN # 2) that is a communication partner of a wireless LAN and a headset (BT # 2) that is a communication partner of Bluetooth. ). In FIG. 3, the WLAN device 1 and the BT device 2 are set as WLAN # 1 and BT # 1, respectively, and around these, WLAN # 3 and # 4 and WLAN # 5 and # 6 perform communication, respectively. It shall be. On the other hand, FIG. 4 is a diagram showing an example of the positional relationship on the frequency axis between the WLAN channels (communication WLAN channels) used by the WLANs # 1 to # 6 shown in FIG. 3 and the FH channels. In FIG. 4, the FH channel that can be used by the BT device 2 is shown as a “good channel”. This good channel is an FH channel that does not interfere with the WLAN device 1 and the surrounding WLAN devices (WLAN # 3 to # 6) even when the BT device 2 is used for communication.

  When the power is turned on, the WLAN device 1 first enters a reception state, sequentially switches the received WLAN channel (channel scan), searches for other WLAN devices in the vicinity for use in communication, It determines which WLAN channel is used to communicate with the communication partner WLAN device (determines a communication WLAN channel). At this time, the channel communication quality in each WLAN channel is acquired.

  For example, when the communication partner of the WLAN device 1 and other surrounding WLAN devices are in the relationship shown in FIGS. 3 and 4, the access point (AP) that is the communication partner is set to the WLAN channel 6 (frequency 2426 MHz to 2448 MHz). Since the WLAN device 1 operates as a wireless LAN terminal, the WLAN device 1 receives the beacon (beacon) of the WLAN channel 6 to perform connection control and exchange data. At this time, if WLAN # 3 and WLAN # 4 communicate on WLAN channel 1 (frequency 2401 MHz to 2423 MHz) and WLAN 5 # and WLAN # 6 communicate on WLAN channel 13 (frequency 2461 MHz to 2483 MHz), channel The result of the scan (information on the communication WLAN channel used by the WLAN device 1 and surrounding WLAN devices) is transmitted to the wireless channel control unit 3 as “used channel information” in consideration of the erroneous detection danger channel, “Channel communication quality information” indicating the degree of interference / interference generated based on information such as bit error rate, packet error rate, RSSI, SINR, and CINR (Carrier to Interference plus Noise Ratio) of each communication WLAN channel To the wireless channel control unit 3. Here, the “false detection risk channel” is an FH channel that may cause an erroneous determination in carrier sense if it is simultaneously used when carrier sensing its own communication WLAN channel. This corresponds to the FH channel within a predetermined range close to the WLAN channel. That is, it is the same as the erroneous detection danger channel described in Patent Document 1 above. The “used channel information” described above includes information on the communication WLAN channel and information on the risk of erroneous detection of each WLAN device.

  In the BT device 2, in the communication state, the link management unit 24 generates the communication quality information described above at a predetermined timing, and notifies the radio channel control unit 3 of the communication quality information. The timing for notifying the communication quality information may be performed at predetermined intervals, or when the fluctuation amount of the communication quality information reaches a specified value (a certain amount from the value at the last notification). You may make it notify when it changes above, ie, when communication quality changes a lot). Further, when a request is received from the radio channel control unit 3, notification may be made. The communication quality information to be notified is not limited to information such as the bit error rate, packet error rate, RSSI, SINR, and CINR described above, and may include information on interference / interference. The communication quality information may be information obtained from a correlation value of a fixed pattern.

  In the radio channel control unit 3 notified of the use channel information, the channel communication quality information, and the communication quality information, the use channel management unit 31 determines an FH channel that can be used by the BT device 2 based on the information. Then, the “usable FH channel information” indicating the determination result is notified to the BT device 2.

  The BT device 2 that has been notified of the usable FH channel information performs frequency hopping communication while switching the channel to be used at a certain time interval for all or part of the FH channel indicated by the usable FH channel information. The switching destination FH channel in the frequency hopping operation is determined by the frequency hopping channel determination unit 23 based on usable FH channel information.

  FIG. 5 is a diagram showing an example of used channel information and channel communication quality information generated by the WLAN device 1, and shows the used WLAN channel (corresponding to the above-described communication WLAN channel), the unusable channel, and the risk of erroneous detection. Each piece of channel information constitutes used channel information. In the case of the example shown in FIG. 5, the interference / interference decreases in the order of the WLAN channel 1 (Ch01) and the WLAN channel 13 (Ch13) with reference to the WLAN channel 6 (Ch06) used by itself. ing. Note that the erroneous detection risk channel differs depending on the design value of the WLAN device 1, and may be notified from the WLAN device (the WLAN devices around the WLAN device 1) in response to a request from the WLAN device 1. The wireless channel control unit 3 may be set for each WLAN device. Further, as described in Patent Document 1, it is possible to notify not only “misdetected dangerous channel” information but also information such as “unusable channel at transmission” and “unusable channel at reception”. . Also, from the viewpoint of operation, if there is an FH channel that you do not want the BT device 2 to communicate with in advance, the FH channel should be set in advance as an unusable channel by the used channel management unit 31. Is also possible. In addition to “busy”, “unusable channel”, and “misdetected danger channel”, “channels that can be used although there is interference from the surroundings (low recommended)”, “for your own wireless LAN channel” It is not recommended to use, such as "Interference channel that does not perform false detection but causes communication quality degradation (low recommendation)", but it can be used when the number of Bluetooth FH channels is insufficient (but low recommended). It is also possible to rank and notify the channel.

  The WLAN device 1 changes the WLAN channel to be used according to a predetermined protocol when it becomes necessary to change the WLAN channel to be used because the quality of the WLAN channel being used is deteriorated. Therefore, the WLAN communication control unit 13 outputs “usable channel information” and “channel communication quality information” to the radio channel control unit 3 every time a change in the WLAN channel to be used occurs. Upon receiving these notifications, the radio channel control unit 3 updates (re-determines) the FH channel that can be used by the BT device 2 with the use channel management unit 31, and if there is a change in the content, The updated usable FH channel information is notified.

  The operation of the used channel management unit 31 of the radio channel control unit 3 will be described below.

  For example, in a state where the WLAN device 1 and the BT device 2 and the other communication devices are in the positional relationship shown in FIG. 3, the “used channel” notified from the WLAN device 1 (WLAN # 1) to the wireless channel control unit 3 When the “information” has the contents shown in FIG. 5, only the 2454 MHz and 2455 MHz FH channels can be used as the good channel by the BT device 2 (see FIG. 4). Therefore, if 20 channels are required as FH channels for the BT device 2 to perform frequency hopping, the radio channel control unit 3 controls the BT device 2 not to perform communication, or as shown in FIG. In addition, among the FH channels classified as unusable channels or false detection risk channels, FH channels that are defective channels for the BT device 2 are selected in an insufficient number, and these selected FH channels and good channels (these channels) are selected. Are collectively referred to as an available FH channel). FIG. 6 is a diagram illustrating an example of the selection result of the usable FH channel. In FIG. 6, the FH channel selected for causing the BT device 2 to use the hatched FH channel (usable FH channel) (The same applies to FIG. 7 and subsequent figures). As a result, not only the conventional WLAN devices (WLAN # 3 to WLAN # 6) have a large interference, but also between the BT devices (BT # 1, BT # 2) as well as the conventional WLAN devices (WLAN # 3 to WLAN # 3). The problem that the tolerance to the interference wave from # 6) deteriorates does not change, but the FH channel that affects the WLAN channel 6 used by the WLAN device 1 is not selected, and the communication of the BT device 2 is prevented. It is possible to prevent the communication of the WLAN device 1 from being affected.

  Further, when selecting an insufficient number of FH channels from the unusable channels or the erroneous detection risk channels, the channel communication quality information value included in the used channel information is small (interfering / interfering). May be selected in order (see FIG. 7). FIG. 7 is a diagram showing an example of the selection result of the FH channel used by the BT device 2 (selection result of the usable FH channel), and shows the selection result when the used channel information has the contents shown in FIG. Yes. This not only interferes with the WLAN device (WLAN # 5, WLAN # 6) using the WLAN channel 13 in the same frequency band as the selected FH channel, but also between the BT devices (BT # 1, BT # 2). However, there is a problem that the resistance to interference waves from the WLAN device (WLAN # 5, WLAN # 6) deteriorates as in the prior art. However, the WLAN channel 6 on which the WLAN device 1 operates and other WLAN devices (WLAN It is possible to prevent the influence of the WLAN channel 1 on which # 3, WLAN # 4) operates. Further, the influence (interference amount) that the communication between the BT devices is affected by other WLAN devices can be suppressed.

  Here, as can be seen from FIG. 4 and FIG. 5 and the like, the misdetection dangerous channel includes the in-use WLAN channel and a certain range close thereto (including the unusable channel and the certain range close thereto). A certain range close to a certain used WLAN channel does not overlap with the frequency band of another used WLAN channel. Therefore, although the FH channel included in the predetermined range corresponding to the frequency band of the erroneously detected dangerous channel minus the frequency band of the in-use WLAN channel (or the unusable channel) is affected by the adjacent WLAN channel. It is not as greatly affected as other misdetection dangerous channels (FH channels not included in the above-mentioned fixed range) (the amount of interference from the WLAN channel is relatively small). Therefore, when selecting the FH channels corresponding to the shortage from those having a small value of the channel communication quality information, the FH channels that are not included in the frequency band of the used WLAN channel (or the unusable channel) are preferentially selected. You may make it do. As a result, it is unavoidable that deterioration in communication quality when an FH channel that is not a good channel is used for frequency hopping communication can be minimized.

  Further, the distance from the neighboring WLAN device is short, and the interference amount from the WLAN channel in use by the other WLAN device is interference from the communication WLAN channel (in-use WLAN channel) of the own device (WLAN device 1). It may be larger than the amount (when the channel communication quality information is large). Even in such a case, the FH channel within the range obtained by subtracting the frequency band of the in-use WLAN channel (or the unusable channel) from the frequency band of the erroneous detection danger channel corresponding to the communication WLAN channel of the own apparatus is preferentially used. select. Thereby, although the influence of interference exists, the amount of interference and transmission timing can be managed, so that the amount of interference can be estimated (the amount of quality degradation can be quantitatively understood). As a result, a decrease in throughput can be suppressed as compared with the case where the FH channel is selected in the vicinity of a WLAN channel (a WLAN channel with a large amount of interference) used by another WLAN device.

  In the case of preferentially selecting an FH channel (FH channel within the proximity range of the used WLAN channel) that is not included in the frequency band of the used WLAN channel (unusable channel) while considering the channel communication quality information. Although shown, the FH channel not included in the frequency band of the in-use WLAN channel (unusable channel) may be preferentially selected without considering the channel communication quality information. In this case, the priority of the FH channel in the proximity range of the in-use WLAN channel of the own apparatus is set lower than the priority of the FH channel in the proximity range of other in-use WLAN channels.

  Also, a threshold is set for the channel communication quality information, and only when the threshold is equal to or less than the threshold, operates to use the FH channel in the same frequency band as the WLAN channel (the FH channel to be selected to compensate for the shortage). , It may be limited to the one corresponding to the WLAN channel below the threshold).

  On the other hand, the communication quality required by the application in the BT device 2 cannot be maintained, such as the quality of the FH channel being used by the BT device 2 is deteriorated, or the available FH channels are less than the desired number of usable channels. In some cases, the BT device 2 transmits to the radio channel control unit 3 "communication quality information" indicating the current communication quality such as PER and BER, the traffic type, the buffer retention amount, and the like. “Bandwidth request information” indicating a bandwidth or a necessary communication bandwidth is notified. When the communication quality management unit 32 of the radio channel control unit 3 determines that the communication state of the BT device 2 is lower than the predetermined communication quality, the communication quality management unit 32 notifies the QoS management unit 33 to that effect. Upon receiving this notification, the QoS management unit 33 considers the QoS between the WLAN device 1 and the BT device 2, and notifies the WLAN device 1 of a channel change request when giving priority to the traffic on the BT device 2 side. Then, control is performed to change the WLAN channel. As a result, when the communication quality of the BT device 2 deteriorates, the wireless communication channel control unit 13 makes a channel change request to the WLAN device 1 and performs a scan of the WLAN channels 1 to 14. It becomes possible to change the frequency.

  In addition, when the amount of communication traffic of the WLAN device 1 is small and it is excessive to make the WLAN device 1 occupy the WLAN channel 16 (that is, the desired communication traffic is sufficiently transmitted even in the WLAN channel used by another WLAN device). (If it is possible to do this) Therefore, the radio channel control unit 3 detects such a state, and when the number of good FH channels is insufficient, notifies the channel change request to the WLAN device 1 to change the WLAN channel. It is also possible to increase the number of good FH channels. At that time, based on the previous channel communication quality information, it is desirable that the LAN device 1 and the BT device 2 move to the WLAN channel with the least interference / interference (the WLAN channel with the smallest channel communication quality information). The communication traffic amount of the WLAN device 1 can be directly acquired from the WLAN device 1 or acquired by the wireless channel control unit 3 via a host interface connected to the WLAN device 1, a driver, or an application layer. It is also possible to do.

  FIG. 8 is a diagram showing a positional relationship of communication WLAN channels when communication of WLAN # 1 and WLAN # 2 is moved to WLAN channel 13 in the environment shown in FIG. By performing this movement (WLAN channel change), the use channel information and the channel communication quality information notified from the WLAN device 1 to the radio channel control unit 3 are changed to those shown in FIG.

  The wireless channel control unit 3 that has received the notification of the used channel information and the channel communication quality information after the change in FIG. 9 transmits the usable FH channel information to the BT device 2, and the currently usable FH channel is 2429 MHz. To 2455 MHz. The BT device 2 actually uses the notified usable FH channel as a good channel for frequency hopping communication. Thereby, although there is a possibility that the throughput of the WLAN device 1 is lowered, it is possible to increase the number of good FH channels that can be used by the BT device 2 and to guarantee the communication quality.

  In the present embodiment, the method of changing the operating frequency of the WLAN device 1 according to the channel communication quality information has been described. However, the present invention is not limited to this, and the communication traffic amount (load amount) is measured and held in each WLAN channel. By doing so, it is possible to move to a WLAN channel with a small amount of communication traffic. Furthermore, it is also possible to determine by combining both channel communication quality information and communication traffic volume.

  In the present embodiment, the transmission power values of the WLAN device 1 and the BT device 2 are not mentioned. However, for example, interference may be a problem in the WLAN channel 13 to which the WLAN device 1 is a destination. . Therefore, the WLAN device 1 confirms its own communication quality, and if there is no problem in communication quality (for example, packet error rate, SINR, CINR exceeds required values), the transmission power may be reduced. Good. Thereby, the interference can be reduced.

  Also, a method of reducing the “false detection dangerous channel”, the “unusable channel at the time of transmission”, and the “unusable channel at the time of reception” by lowering the transmission power of the BT device 2 can be considered. That is, when the transmission power of the WLAN device 1 and the BT device 2 has no problem in its own communication quality (for example, the packet error rate, SINR, and CINR exceed the required values), the transmission power is reduced. , Interference with other wireless communication devices (wireless communication devices including WLAN devices and BT devices) is reduced. As a result, the interference problem in a plurality of wireless communication devices can be reduced.

  Furthermore, as shown in FIG. 10, a canceller taking into account the antenna characteristics and filter characteristics of the WLAN device 1 is arranged between the WLAN device 1 and the BT device 2, and when the WLAN device 1 transmits, the canceller is operated. It is also possible to improve the reception characteristics of the BT device 2 by reducing interference by canceling the sneak power from the WLAN device 1. In FIG. 10, the canceller for the transmission waveform of the WLAN device 1 is described. However, by providing a canceller corresponding to the transmission of the BT device 2 (canceller having a reverse characteristic of the transmission wrap by the BT device 2), Interference in the WLAN device 1 can be reduced and reception characteristics can be improved. This makes it possible to reduce the “false detection dangerous channel”, “unusable channel during transmission”, and “unusable channel during reception”.

  As described above, in this embodiment, the WLAN device 1 confirms the channel (communication WLAN channel) used in other neighboring WLAN devices when the power is turned on or when the channel to be used is switched, and the communication WLAN channel is determined. The channel communication quality information for each is generated, and the BT device 2 uses the used channel information generated based on the confirmation result of the communication WLAN channel, the bit error rate, the packet error rate, the RSSI, the SINR of the communication WLAN channel. The frequency hopping communication is performed using the usable FH channel determined based on the channel communication quality information indicating the degree of interference / interference generated based on CINR and the like. Further, when the communication quality in the BT device 2 deteriorates and the bandwidth becomes insufficient, the WLAN device 1 changes the WLAN channel to be used to a channel that has less influence (interference) on the communication of the BT device 2. As a result, the WLAN device and the BT device are arranged close to each other (for example, both the BT device and the WLAN device are mounted on the wireless communication device), and there are a plurality of WLAN devices and BT devices, and the FH for frequency hopping communication. Even if the channel cannot be sufficiently secured, the occurrence of erroneous carrier sense detection in the WLAN device is avoided, and mutual interference is avoided to satisfy the required bandwidth required by the BT device (frequency hopping communication). Can secure the required number of FH channels).

Embodiment 2. FIG.
Next, the radio communication apparatus according to the second embodiment will be described. FIG. 11 is a diagram illustrating a configuration example of the wireless communication device according to the second embodiment, and the wireless communication device includes a WLAN device 1a, a BT device 2a, and a wireless channel control unit 3a. Note that the same reference numerals are assigned to the same components as those of the wireless communication apparatus according to the first embodiment. The description of the components given the same reference numerals will be omitted.

  The WLAN device 1a includes a WLAN wireless unit 11 and a WLAN communication control unit 13a. The WLAN communication control unit 13a includes an access control unit 14a, and receives bandwidth request information (details will be described later) from the radio channel control unit 3a in addition to the functions of the WLAN communication control unit 13 described in the first embodiment. In this case, based on this bandwidth request information, a function (bandwidth allocation) for allocating a fixed time among the operation times allocated from the WLAN device (access point) facing the own device (WLAN device 1a) to the BT device 2A. Function).

  On the other hand, the BT device 2a includes a BT radio unit 21 and a BT communication control unit 22a. The BT communication control unit 22a includes a frequency hopping channel determination unit 23a and a link management unit 24. When receiving usable FH channel information and usable time information (details will be described later) from the radio channel control unit 3a, the BT communication control unit 22a receives these information. The frequency hopping communication is performed after the FH channel used by the frequency hopping channel determination unit 23a is selected based on the above.

  The radio channel control unit 3a includes a use channel management unit 31a, a communication quality management unit 32, and a QoS management unit 33. Based on the information received from the BT device 2a and the information received from the WLAN device 1a, the radio channel control unit 3a On the other hand, the FH channel permitted to be used is determined and the usable time information is generated. Further, when the bandwidth request information is received from the BT device 2a, the bandwidth request information is notified to the WLAN device 1a.

  Next, the overall operation of the wireless communication apparatus according to the present embodiment will be described. Similar to the explanation of the operation in the first embodiment, the operation (interference reduction method) for reducing the mutual interference between the communication of the WLAN device 1 and the communication of the BT device 2, which is a characteristic operation, and this The explanation will focus on the operations related to. The description will be made with reference to FIGS.

  12-14 is a figure for demonstrating operation | movement of the radio | wireless communication apparatus of Embodiment 2. FIG. FIG. 12 shows an example of the operating environment of the wireless communication apparatus of this embodiment. In FIG. 12, the mobile terminal corresponds to the wireless communication apparatus of the present embodiment, and communicates with a WLAN access point (WLAN # 2) that is a communication partner of a wireless LAN and a headset (BT #) that is a Bluetooth communication partner. 2) A case where communication is performed is shown. In FIG. 12, the WLAN device 1a and the BT device 2a are designated as WLAN # 1 and BT # 1, respectively. The environment shown in FIG. 12 is obtained by adding WLANs # 7 and # 8 to the environment assumed in the description of the first embodiment (the environment shown in FIG. 3), and a WLAN access point. There are three terminals connected to (WLAN # 2), WLAN # 1 (WLAN apparatus 1a), # 7, and # 8. FIG. 13 is a diagram showing an example of the positional relationship on the frequency axis of the WLAN channels (communication WLAN channels) used by the WLANs # 1 to # 8 shown in FIG.

  In the environment shown in FIG. 12, WLAN # 3 and WLAN # 4 communicate using WLAN channel 1 (CH1: 2401 to 2423 MHz), which is a channel defined by IEEE802.11b / g / n. # 1, WLAN # 2, WLAN # 7 and WLAN # 8 communicate using WLAN channel 6 (CH6: 2426 to 2448 MHz), and WLAN # 5 and WLAN # 6 are WLAN channel 11 (CH11: 2451 to 2473 MHz). ), The radio channel control unit 3a of the present embodiment selects an FH channel that is allowed to be used for the BT device 2a as shown in FIG. That is, the radio channel control unit 3a first determines an FH channel (center frequencies are 2424 MHz, 2425 MHz, and 2449 MHz) that do not overlap the WLAN channels (communication WLAN channels) 1, 6, and 11 used in the WLANs # 1 to # 8. , 4 FH channels of 2450 MHz and 7 FH channels between 2474 MHz and 2480 MHz in total (11 FH channels) are selected as good channels (available FH channels), and frequency hopping communication becomes possible As described above, four or more FH channels farthest from the WLAN channel 6 in use by the WLAN device 1a are additionally selected from the insufficient FH channels. For example, an FH channel in the range of 2402 to 2405 MHz and 2472 to 2473 MHz is additionally selected. Then, the combination of the FH channel selected as the good channel and the additionally selected FH channel is notified to the BT device 2a as the usable FH channel (available FH channel information indicating the selected FH channel is notified). To do). Similar to the operation described in the first embodiment, the selection operation may be performed in consideration of the erroneous detection risk channel, the transmission unavailable channel, and the reception unavailable channel. In FIG. 13, the additionally selected FH channel is described as a defective channel.

  FIG. 14 shows a sequence in the case where the WLAN device 1a (WLAN # 1) transmits data to the WLAN access point (WLAN # 2). The BT device 2a affected by this data transmission operation and other The operation of the WLAN device (WLAN # 7, # 8) is also described.

  In FIG. 14, a sequence in which WLAN # 1 and WLAN # 2 perform Beacon transmission and reception and data communication using RTS / CTS is described from time t0 to t1. In IEEE802.11b / g / n, other terminals operating on the same WLAN channel that received NAV (Network Allocation Vector) information in a communication frame hold communication for the notified time (time indicated by NAV information). To do. In the example of FIG. 14, WLANs # 7 and # 8, which are Others, correspond to other terminals, and a portion described in gray (hatched portion) is a section corresponding to NAV information, and communication is suspended in this section It shows how they are doing. It is assumed that the BT device 2 and the opposite BT device (communication partner) are operating on the used FH channel determined based on the usable FH channel information notified from the radio channel control unit 3a. It is assumed that the good channel and the bad channel are used FH channels.

  That is, in the wireless communication device of the present embodiment, the WLAN device 1a (WLAN # 1) performs data transmission by executing the sequence shown in the section from time t0 to time t1 shown in FIG. On the other hand, the BT device 2a performs frequency hopping communication using the good channel and the bad channel shown in FIG. From time t1 to time t2, the WLAN device 1a causes the NAV to suspend communication with the communication partner WLAN # 2 and other terminals (WLAN # 7 and # 8 shown as Others) operating on the same WLAN channel. The CTS-to-itself frame including the frame is transmitted so that WLAN communication does not occur for a certain period of time (t2-t1 time-CTS-to-itself frame transmission time). In addition, the WLAN device 1a notifies the radio channel control unit 3a of bandwidth allocation time information indicating the same reserved bandwidth time (time indicated by the NAV information) as that included in the transmitted CTS-to-itself frame. . Receiving this notification, the wireless channel control unit 3a determines the usable FH channel based on the notification content and the used channel information previously notified and held from the WLAN device 1a, and further, the determination result Usable FH channel information and the expiration date (which corresponds to a period during which the WLAN device 1a or the like stops communication, and is a period from t1 to t2 in FIG. 14) are transmitted to the BT device 2a. Notify them. When receiving the notification of the usable FH channel information and the usable time information from the radio channel control unit 3a, the BT device 2a recognizes that the WLAN channel 6 used by the WLAN device 1a has been released for its own communication. 15, the FH channel selected from the FH channels included in the range of 2424 to 2450 MHz and 2474 to 2480 MHz (however, the number of FH channels more than the minimum necessary for frequency hopping communication) is used. To perform frequency hopping communication. When the section from time t1 to t2 ends, the BT device 2a returns to communication using the same FH channel as the FH channel used in the section from time t0 to t1.

  The operation shown in FIG. 14 is executed when the BT device 2a notifies the wireless channel control unit 3a of bandwidth request information. That is, when the BT device 2a outputs the bandwidth request information, this is notified to the WLAN device 1a via the radio channel control unit 3a, and the WLAN device 1a that has received the notification of the bandwidth request information transmits a CTS-to-itself frame. Thus, the WLAN channel 6 used by the own device and the surrounding WLANs # 7 and # 8 is opened for a certain period (t1 to t2).

  In this way, by lending the WLAN channel used by the WLAN device 1a to the BT device 2a for a certain period of time, the WLAN channel can be adaptively adapted to traffic that requires communication quality guarantee and traffic with severe time restrictions. Can be released, and it is possible to achieve a desired throughput while avoiding interference.

  In the present embodiment, an example has been described in which a CTS-to-itself frame is used for releasing a WLAN channel. However, the present invention is not limited to this, and is not limited to this. ) Or the like. Further, the frame type is not limited as long as the same effect can be realized.

  Further, control (determination of usable FH channel) may be performed in consideration of the erroneous detection risk channel, the transmission unavailable channel, the reception unavailable channel, and the like described in the first embodiment.

  Further, the WLAN device 1a recognizes the communication status of surrounding WLAN devices based on the channel communication quality information, and then changes the operating frequency (the WLAN channel to be used) shown in the first embodiment and the present embodiment. It is also possible to use a combination of the indicated communication time allocations (control in which communication on the used WLAN channel is stopped for a certain period and used by the BT device 2a).

  As described above, in the wireless communication device according to the present embodiment, when the communication quality deteriorates and the bandwidth becomes insufficient, the BT device notifies the WLAN device via the wireless channel control unit of bandwidth request information for requesting a new bandwidth allocation. When the WLAN device receives the bandwidth request information, the WLAN device uses the same channel as the WLAN channel (communication WLAN channel) used by the own device for the communication device of the communication partner and the surrounding communication devices. A request was made not to carry out communication for a certain period. In a period in which this communication is not performed, the BT device performs frequency hopping communication using the FH channel having the same band as the communication WLAN channel set not to be used. This makes it possible to efficiently allocate a good channel to the BT device, and allocate a band that satisfies a desired communication quality to a BT terminal that performs communication with a relatively high QoS such as a voice packet while avoiding interference. be able to.

  As described above, the wireless communication apparatus according to the present invention is useful for a composite wireless apparatus including a plurality of different communication apparatuses, and in particular, each of the included communication apparatuses communicates using a channel in the same frequency band. Suitable for wireless communication devices.

1, 1a WLAN device 2, 2a BT device 3, 3a Radio channel control unit 11 WLAN radio unit 12 Carrier sense unit 13, 13a WLAN communication control unit 14, 14a Access control unit 21 BT radio unit 22, 22a BT communication control unit 23 , 23a Frequency hopping channel determination unit 24 Link management unit 31, 31a Used channel management unit 32 Communication quality management unit 33 QoS management unit

Claims (24)

A WLAN device that performs an operation in accordance with the wireless LAN standard, and generates channel information used by the own device and other communication devices in the surroundings when performing a channel scan;
A BT device that performs operations in accordance with the Bluetooth standard;
A radio channel controller that determines a channel that can be used by the BT device based on channel information generated by the WLAN device;
With
The BT device performs frequency hopping communication according to the determination result in the radio channel control unit, and notifies the radio channel control unit of a shortage band or a necessary band when a deterioration in communication quality is detected. ,
When the radio channel control unit receives a notification of insufficient bandwidth or necessary bandwidth from the BT device, the wireless channel control unit instructs the WLAN device to change the used channel or temporarily stop communication in the used channel. A wireless communication device. When receiving an instruction to change the use channel from the wireless channel control unit, the WLAN device changes the use channel according to the instruction content and updates the channel information.
The radio communication apparatus according to claim 1, wherein the radio channel control unit re-determines a channel that can be used by the BT apparatus based on the updated channel information. The WLAN device further generates communication quality information of each channel used by itself or another communication device when performing a channel scan,
When the wireless channel control unit instructs the WLAN device to change the used channel, the wireless channel control unit determines the used channel after the change based on the communication quality information, and instructs the change to the determined channel. The wireless communication apparatus according to claim 1 or 2.   The wireless communication apparatus according to claim 3, wherein the WLAN apparatus generates the communication quality information based on a traffic type and a QoS type.   5. The radio channel controller according to claim 3, wherein the radio channel control unit identifies a channel having the least interference / interference based on the communication quality information, and instructs to change to the identified channel. Wireless communication device.   The radio channel control unit, when determining channels that can be used by the BT device, selects a predetermined number of channels in order from the channel with the least interference / interference based on the communication quality information. The wireless communication apparatus according to claim 3, 4 or 5.   The wireless channel control unit is a channel used by the WLAN device or the other communication device when there are a plurality of channels having the same amount of interference / interference specified based on the communication quality information. 7. The wireless communication apparatus according to claim 6, wherein a channel that is not included in the frequency band of the WLAN channel is preferentially selected.   When determining a channel that can be used by the BT device, the radio channel control unit prioritizes a channel that is not included in a frequency band of a WLAN channel that is used by the WLAN device or the other communication device. The wireless communication device according to claim 1, wherein the wireless communication device is selected automatically.   The wireless channel control unit is a channel that is not included in a frequency band of a WLAN channel that is a channel used by the WLAN device or the other communication device when determining a channel that can be used by the BT device. The wireless communication apparatus according to any one of claims 1 to 5, wherein the wireless communication apparatus selects in order from the channel with the smallest amount of interference from the WLAN channel.   The wireless communication apparatus according to claim 6, wherein the wireless channel control unit selects a predetermined number of channels or more required for frequency hopping communication. When the WLAN device is instructed to temporarily stop communication in the used channel by the wireless channel control unit, the WLAN device stops communication in the used channel for a certain period of time with respect to the communication device of the communication partner and other surrounding communication devices. Stop the communication for a certain period after instructing
The wireless channel control unit permits the BT device to communicate using a channel in the same frequency band as the channel in which communication is stopped during the period in which the WLAN device has stopped communication. The wireless communication apparatus according to claim 1.   The BT device returns to communication on a channel used before the WLAN device stops communication after a period during which the WLAN device stops communication. 11. A wireless communication device according to 11. WLAN device that performs communication according to the wireless LAN standard, BT device that performs communication according to the Bluetooth standard, and a wireless channel control unit that determines a channel that can be used by the BT device based on information obtained from the WLAN device A bandwidth control method to be executed by a wireless communication device comprising:
A channel information generation step in which the WLAN device performs channel scan and generates information on channels used by the own device and other communication devices in the vicinity;
The wireless channel control unit determines an available channel based on the channel information, and determines a channel that can be used by the BT device;
Request band for notifying the radio channel control unit of a shortage band or a necessary band when the BT device detects deterioration of communication quality during frequency hopping communication according to the determination result in the radio channel control unit A notification step;
When the wireless channel control unit receives a notification of an insufficient bandwidth or a necessary bandwidth from the BT device, an operation instruction for instructing the WLAN device to change a used channel or temporarily stop communication in the used channel Steps,
A bandwidth control method comprising: When the use channel change instruction is given in the operation instruction step,
The WLAN device changes the use channel according to the instruction content in the operation instruction step and updates the channel information,
The band control method according to claim 13, wherein the radio channel control unit re-determines a channel that can be used by the BT device based on the updated channel information. In the channel information generation step, communication quality information of each channel used by the own device or another communication device is further generated,
In the operation instruction step, when an instruction to change the use channel is given to the WLAN device, the use channel after the change is determined based on the communication quality information, and the change to the determined channel is instructed. The band control method according to claim 13 or 14.   The bandwidth control method according to claim 15, wherein the communication quality information is generated based on a traffic type and a QoS type.   The band according to claim 15 or 16, wherein in the operation instruction step, a channel with the least interference / interference is identified based on the communication quality information, and a change to the identified channel is instructed. Control method.   18. The usable channel determining step selects a predetermined number of channels in order from the channel with the least interference / interference based on the communication quality information. Bandwidth control method.   In the usable channel determination step, when there are a plurality of channels having the same amount of interference / interference specified based on the communication quality information, the channel used by the WLAN device or the other communication device is used. The band control method according to claim 18, wherein a channel not included in a frequency band of a certain WLAN channel is preferentially selected.   14. The usable channel determination step preferentially selects a channel that is not included in a frequency band of a WLAN channel that is a channel used by the WLAN device or the other communication device. The bandwidth control method according to any one of ˜17.   In the usable channel determination step, a channel that is not included in a frequency band of a WLAN channel that is a channel used by the WLAN device or the other communication device and that has the smallest amount of interference from the WLAN channel. The bandwidth control method according to claim 13, wherein the bandwidth control method is selected in order.   The band control method according to any one of claims 18 to 21, wherein, in the usable channel determination step, channels of a specified number or more required for frequency hopping communication are selected. When it is instructed to temporarily stop communication in the use channel in the operation instruction step,
The WLAN device instructs the communication device of the communication partner and other surrounding communication devices to stop the communication in the use channel for a certain period, and then stops the communication for a certain period.
The wireless channel control unit permits the BT device to communicate using a channel in the same frequency band as the channel in which communication is stopped during the period in which the WLAN device has stopped communication. The bandwidth control method according to claim 13.   The BT device returns to communication on a channel used before the WLAN device stops communication after a period during which the WLAN device stops communication. 23. The bandwidth control method according to 23.

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