JP2004153394A - Radio terminal device, adapter for radio communication, computer program, and radio communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically switch frequency ranges to be used in response to indoor-outdoor use. <P>SOLUTION: When being supplied power form a main body of a personal computer, the state of a radio communication method goes into a waiting state (S401). While setting a switch 307 for switching transmitting/receiving on a receiving side (S402), the method keeps watching of receiving of a beacon from an access point (S403). When detecting a carrier in a 4.9 GHz range in the waiting state (S403Y, 404Y), the method sets a communication mode with a carrier in the 4.9 GHz range usable out of doors (S405). On the other hand, when detecting a carrier in a 5.2 GHz range (S403Y, 404N), the method sets a communication mode with a carrier in the 5.2 GHz range usable only in doors (S406). Then, after switching the switch 307 to a transmitting side (S407), the method communicates with the access point (S408). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wireless terminal device and the like, and more particularly, when at least one carrier frequency is restricted to indoor use, automatically switches the carrier frequency according to indoor and outdoor use. The present invention relates to a possible wireless terminal device, wireless communication adapter, computer program, recording medium, and wireless communication method.
[0002]
[Prior art]
Recently, wireless LANs have been widely used. The wireless LAN is standardized by IEEE 802.11, and a service and a compatible device based on IEEE 802.11b that uses a frequency of the 2.4 GHz band as a carrier and provides high-speed communication at 11 Mbps have become widespread. With the use of the Internet, network services called hot spots are also spreading.
[0003]
More recently, services and compatible devices compliant with IEEE802.11a that use a frequency in the 5.2 GHz band as a carrier and provide 54 Mbps higher speed communication have been gradually spreading.
[0004]
Under such circumstances, so-called wireless LAN adapters, which are wireless communication adapters for providing a computer with a wireless communication function, are provided in a type compliant with IEEE802.11b and a type compliant with IEEE802.11a. So-called combo types for both are gradually being offered.
[0005]
By the way, the 2.4 GHz band, which is a carrier of IEEE802.11b, can be used both indoors and outdoors, whereas the 5.2 GHz band, which is a carrier of IEEE802.11a, is a frequency band used for weather radar and the like. Therefore, indoor use is restricted, and if used, it would violate the Radio Law.
[0006]
Therefore, in order to enable communication based on IEEE802.11a even outdoors, use of the 4.9 GHz band has recently been secured. Therefore, if the communication of the 4.9 GHz band is performed in IEEE802.11a, the above-mentioned problem does not occur.
[0007]
However, in the case of providing a wireless LAN adapter that can use both the 5.2 GHz band and the 4.9 GHz band in IEEE 802.11a, a mechanism for preventing the 5.2 GHz band carrier from being transmitted outdoors is implemented. Is needed. Also, for the combo type wireless LAN adapter described above, when the 5.2 GHz band is used, it is necessary to implement the above-described mechanism. That is, in providing a wireless LAN adapter using at least the 5.2 GHz band, it is necessary to implement a mechanism that prevents the 5.2 GHz band carrier from being transmitted outdoors.
[0008]
Conventionally, as a means for providing such a mechanism, wireless communication including an indoor determination unit that determines whether indoor or outdoor by detecting a ceiling from reflected waves using radio waves, infrared rays, and ultrasonic waves. An apparatus is known (see Patent Document 1). By using such an indoor determination unit, the frequency to be used indoors and the frequency to be used indoors are switched.
[0009]
[Patent Document 1]
JP 2001-136117 A
[0010]
[Problems to be solved by the invention]
However, in the above-described conventional wireless communication device, a special sensor or circuit such as a light-emitting element or a light-receiving element is provided for determining indoors and outdoors, so that the device is not only large, but also the height of the ceiling, the shape, and the material. In many cases, correct detection results cannot be obtained for indoor / outdoor determination due to factors such as the above, and there has been a problem that the determination accuracy is extremely low.
[0011]
Therefore, an object of the present invention is to automatically switch the use frequency band according to use indoors and outdoors when there is a frequency restricted to indoor use among a plurality of carrier frequencies. To provide a wireless communication device, a wireless communication adapter, a computer program, a recording medium, and a wireless communication method.
[0012]
[Means for Solving the Problems]
An object of the present invention is to provide a wireless communication unit that performs wireless communication with a base station by selecting any one of a plurality of frequencies including a frequency restricted to indoor use, and the wireless communication unit When receiving a special signal, comprises a indoor determination means for determining whether the current position is indoors from the signal, the wireless communication means, when the indoor determination means determined indoors, This is achieved by a wireless terminal device which selects a frequency restricted to use indoors and selects a frequency not restricted to use indoors when the indoor determination means determines that the frequency is outdoor. You.
[0013]
According to the present invention, the frequency can be automatically switched in accordance with use indoors and outdoors without adding a special sensor or circuit, and a radio signal having a frequency exclusive for indoors is erroneously transmitted outdoors. Can be prevented.
[0014]
In a preferred embodiment of the present invention, transmission is prohibited until the wireless communication unit determines whether or not the indoor determination unit is indoors.
[0015]
According to the preferred embodiment of the present invention, it is possible to reliably prevent a situation in which a radio signal having a frequency exclusive for indoor use is erroneously transmitted outdoors.
[0016]
In a further preferred embodiment of the present invention, the special signal is a signal transmitted from the base station.
[0017]
According to a further preferred embodiment of the present invention, it is not necessary to generate a signal for determining whether or not the vehicle is indoors by using a special sensor or a circuit. Can be performed more reliably.
[0018]
In a further preferred embodiment of the present invention, the indoor determination means determines that the current position is indoors when the signal is a frequency restricted to use indoors, the signal is indoors It is determined that the current position is outdoors when the frequency is not restricted to the use of.
[0019]
According to a further preferred embodiment of the present invention, it is not necessary to generate a signal for determining whether or not the vehicle is indoors by using a special sensor or a circuit. Can be performed more reliably.
[0020]
In a further preferred embodiment of the present invention, the indoor determination means, as the signal, a signal of a frequency restricted to use indoors, and a signal of a frequency not restricted to use indoors almost simultaneously When the signal is received, the signal with the strongest radio field intensity is preferentially selected to determine whether or not the signal is indoors.
[0021]
According to a further preferred embodiment of the present invention, when a plurality of signals having different carrier frequencies are received at the same time, a signal having a stronger radio field intensity is prioritized, so that more stable communication with the base station is realized. be able to.
[0022]
In a further preferred embodiment of the present invention, the indoor determination means, as the signal, a signal of a frequency restricted to use indoors, and a signal of a frequency not restricted to use indoors almost simultaneously When the signal is received, a signal of a frequency not restricted to use indoors is preferentially selected to determine whether the signal is indoors.
[0023]
According to a further preferred embodiment of the present invention, when a plurality of signals having different carrier frequencies are received at the same time, a signal of a frequency that is not limited to the indoor use is prioritized, so that the use is restricted to indoor use. It is possible to reliably prevent a signal of the frequency having been transmitted from being erroneously transmitted outdoors.
[0024]
In a further preferred embodiment of the present invention, the indoor determination means, as the signal, a signal of a frequency restricted to use indoors, and a signal of a frequency not restricted to use indoors almost simultaneously When the signal is received, a signal of a frequency restricted to use indoors is preferentially selected to determine whether the signal is indoors.
[0025]
According to a further preferred embodiment of the present invention, when a plurality of signals having different carrier frequencies are received at the same time, the signal of the frequency restricted to the indoor use is prioritized. If communication using a carrier frequency is faster than communication using a carrier frequency that is not restricted to indoor use, communication that emphasizes higher speed may be provided. it can.
[0026]
The object of the present invention is also a wireless communication adapter for providing a wireless communication function to a computer by connecting the computer to a wireless communication adapter, the wireless communication adapter being adapted to select one of a plurality of frequencies including a frequency restricted to indoor use. Wireless communication means for selecting one of them and performing wireless communication with a base station; and when the wireless communication means receives a special signal, it is determined whether or not the current position is indoors from the signal. When the indoor determination means is determined to be indoors, the wireless communication means selects a frequency restricted to use indoors, and when the indoor determination means determines that the indoors are outdoors, The present invention is also achieved by a wireless communication adapter characterized in that a frequency not limited to indoor use is selected.
[0027]
The object of the present invention also provides a computer having a wireless communication function to perform wireless communication with a base station by selecting any one of a plurality of frequencies including a frequency restricted to indoor use. Wireless communication means, and indoor determination means for determining whether the current position is indoors from the signal when the wireless communication means receives a special signal, wherein the wireless communication means When the means is determined to be indoors, a frequency limited to use indoors is selected, and when the indoor determination means is determined to be outdoors, frequencies not limited to use indoors are selected. It is also achieved by a computer program for functioning as a terminal device.
[0028]
The above object of the present invention is also achieved by a computer-readable recording medium on which the computer program is recorded.
[0029]
The above object of the present invention is also a method of performing radio communication with a base station by selecting any one of a plurality of frequencies including a frequency restricted to indoor use, a special signal When receiving, the step of determining whether the current position is indoors from the signal, and, if determined to be indoors, select a frequency restricted to use indoors, if determined to be outdoor And a step of selecting a frequency that is not restricted to indoor use.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0031]
FIG. 1 is a schematic block diagram showing a configuration of a wireless terminal device according to a preferred embodiment of the present invention.
[0032]
As shown in FIG. 1, a wireless terminal device 100 is a computer to which a wireless LAN adapter is connected, and is used for a CPU 101, a memory 102, a hard disk drive (HDD) 103, and a recording medium such as a flexible disk drive or a CD-ROM. A removable media drive (RMD) 104 for recording / reproducing data, an input / output interface (I / O) 105 for connecting to an external device, and a wireless LAN adapter 106 for providing a wireless network interface to a computer are provided. 107 are connected. Further, data input means such as a keyboard 108 and a mouse 109 and display means such as a display 110 are connected via the input / output interface 105.
[0033]
An OS, various device drivers, and various application software are installed in the wireless terminal device 100. These also include a device driver for the wireless LAN adapter 106 and software for network communication. The wireless terminal device 100 functions by cooperation of these software and the above-described hardware, and can perform packet communication called an infrastructure mode with an access point serving as a base station for the wireless terminal device. it can.
[0034]
That is, the transmission data is transferred from the computer main body side to the wireless LAN adapter 106 via the bus 107, modulated, and then transmitted as a wireless signal. Conversely, the wireless signal from the access point is received by the wireless LAN adapter, demodulated, transferred to the computer body via the bus 107, and processed by the CPU 101.
[0035]
When the wireless terminal device 100 connects to an access point, the wireless terminal device 100 receives a beacon periodically broadcast from the access point, thereby detecting an access point in a service area. If the access point authenticates the connection after transmitting the connection request packet to any of them, the connection is established, so that packet communication in the infrastructure mode can be performed.
[0036]
At this time, the wireless terminal device 100 receives the beacon broadcast from the access point, but can simultaneously detect the carrier frequency of the beacon. The carrier frequency is often set in the 5.2 GHz band for an access point installed indoors, but may be set in the 4.9 GHz band. On the other hand, an access point installed outdoors is always set to the 4.9 GHz band according to the Radio Law. Therefore, the wireless terminal device 100 can determine whether the current position is outdoors or indoors from the carrier frequency of the beacon broadcasted from the access point.
[0037]
FIG. 2 is a schematic block diagram illustrating the configuration of the wireless LAN adapter 106.
[0038]
As shown in FIG. 2, the wireless LAN adapter 106 includes a bus interface (I / F) 201 connected to the computer main unit via a bus, a controller 202 that controls between the bus interface 201 and the baseband unit 203, A baseband unit (BB unit) 203 for performing modulation by a spread communication method or the like, an RF unit 204 for performing RF processing on the modulated signal, an antenna 205, and a memory 206 for storing a protocol control program and various data. ing.
[0039]
The packet transmitted from the computer main body is input via the bus interface unit 201, processed in the order of the controller 202, the baseband unit 203, and the RF unit 204, and transmitted as a wireless signal from the antenna 205. Further, a packet sent from the access point AP is received as a radio signal by the antenna 205, then processed in the order of the RF unit 204, the baseband unit 203, and the controller 202, and transmitted to the computer main body via the bus interface 201. Sent out.
[0040]
FIG. 3 is a block diagram illustrating an example of the configuration of the RF unit 204.
[0041]
As shown in FIG. 3, the RF unit 204 includes a transmitting unit 301, a transmitting amplifier 302, and a bandpass filter (BPF) 303 on the transmitting side, and a receiving unit 304, a receiving amplifier 305, and a bandpass filter (BPF) on the receiving side. ) 306, and the two band-pass filters 303 and 306 are connected to the antenna 205 via a switch 307 for switching between transmission and reception. Further, a frequency synthesizer 308 that generates a carrier frequency of 5.2 GHz or 4.9 GHz is connected to the transmission unit 301 and the reception unit 304. Further, the receiving section 304 is connected to a determining section 309 for determining the carrier frequency of the received signal.
[0042]
On the transmitting side, the baseband signal is converted into an RF signal by the transmitting unit 301, amplified by the transmitting amplifier 302, further shaped by the BPF 303, and transmitted via the switch 307 and the antenna 205. On the receiving side, the RF signal input via the antenna 205 and the switch 307 is waveform-shaped by the BPF 306, further amplified by the receiving amplifier 305, and then dropped by the receiving unit 304 into a baseband signal. Sent to
[0043]
The indoor / outdoor determination and the selection of the carrier frequency are performed as follows. First, when the wireless terminal device communicates with the access point, it receives a beacon periodically broadcast from the access point. The beacon is a signal transmitted at the first timing when the access point starts communication in order to inform the existence of the access point. The frequency band of the beacon is set to either 4.9 GHz or 5.2 GHz depending on whether the access point is installed indoors or outdoors. Therefore, first, in the standby state, the transmission / reception changeover switch 307 of the RF unit is set to the receiving side so that the beacon can be received. Therefore, a signal in the 4.9 GHz band or a signal in the 5.2 GHz band is not transmitted from the transmission side.
[0044]
Upon receiving the beacon from the access point, the RF signal is sent to the receiving unit for processing, and the frequency band of the RF signal is determined by the determining unit 309. The result of the determination is sent to the controller 202.
[0045]
Controller 202 further determines whether the access point is installed indoors or outdoors. If the beacon is a signal of 4.9 GHz, since the access point is set to the 4.9 GHz band, it can be determined that the access point may be installed outdoors. Further, in the case of a signal of 5.2 GHz, since the access point is set to the 5.2 GHz band, it can be determined that the access point is installed indoors.
[0046]
When transmitting a packet to the access point, the controller sets a carrier frequency according to the above determination result. If it is determined that the access point is set to the 4.9 GHz band, the carrier frequency of the wireless LAN adapter is also set to 4.9 GHz, and if it is determined that the access point is set to the 5.2 GHz band. For example, the carrier frequency of the wireless LAN adapter is also set to 5.2 GHz. Since the setting signal is input to the frequency synthesizer 308 of the RF unit, the frequency synthesizer 308 generates the set carrier frequency, and the transmitting unit generates the RF signal. Thereafter, the transmission / reception switch is switched to the transmission side, and the transmission of the radio signal is performed.
[0047]
FIG. 4 is a flowchart illustrating an example of a carrier selection procedure by the wireless LAN adapter.
[0048]
As shown in FIG. 4, when power is supplied from the personal computer main body and the wireless LAN adapter starts operating, the wireless LAN adapter enters a standby state (S401), and the transmission / reception switch 307 is set to the receiving side (S402). , And continues to monitor the reception of the beacon from the access point (S403). Therefore, in the standby state, neither carrier in the 4.9 GHz band nor the carrier in the 5.2 GHz band is transmitted.
[0049]
When a carrier of the 4.9 GHz band is detected in the standby state (S403Y, 404Y), a communication mode using the 4.9 GHz band as a carrier that can be used outdoors is set (S405). After the transmission / reception switch 307 is switched to the transmission side (S407), a connection request packet is transmitted to the access point in the set communication mode, and communication is performed between the access points (S408).
[0050]
If a carrier in the 5.2 GHz band is detected in the standby state (S403Y, 404N), the communication mode is set to the 5.2 GHz band that can be used only indoors as a carrier (S406). After the transmission / reception switch 307 is switched to the transmission side (S407), a connection request packet is transmitted to the access point in the set communication mode, and communication is performed between the access points (S408).
[0051]
As described above, according to this embodiment, when the carrier in the 5.2 GHz band is restricted for indoor use, indoor / outdoor determination is performed based on the frequency of the beacon transmitted from the access point. Since either 5.2 GHz or 4.9 GHz carrier frequency is selected from the determination result, the frequency band to be used can be automatically switched according to indoor or outdoor use. Therefore, even in the case where the communication of 5.2 GHz is performed indoors and then the communication of 4.9 GHz is performed outdoors, it is possible to prevent an accident in which a signal of 5.2 GHz is erroneously transmitted.
[0052]
Next, the operation when the 4.9 GHz band and the 5.2 GHz band are received almost simultaneously will be described.
[0053]
FIG. 5 is a diagram illustrating an example of a screen for setting the priority of selection of the carrier frequency.
[0054]
As shown in FIG. 5, on this setting screen 500, a check box for setting a carrier frequency is provided. In detail, a check box 501 for setting to give priority to “higher radio wave intensity” of the two carriers, a check box 502 for setting to give priority to “4.9 GHz”, and “ A check box 503 is provided for setting to give priority to “5.2 GHz”. By clicking these, the settings can be determined and changed. This setting information is stored in the memory 206 in the wireless LAN adapter or in the memory 102 in the computer.
[0055]
In the initial setting, as shown in the figure, a check box 501 for “prioritizing the radio wave intensity” is set to on, a check box 502 for “priority to 4.9 GHz” is turned on, and “priority to 5.2 GHz” is set. The check box 503 is set to off. Therefore, when two carriers are received at the same time, the higher radio wave intensity is preferentially selected, and if the radio wave intensities of both carriers are almost equal, the 4.9 GHz carrier is preferentially set.
[0056]
When the check box 503 for “prioritizing 5.2 GHz” is turned on on the setting screen, the opposite check box 502 for “prioritizing 4.9 GHz” is automatically turned off. By changing the setting in this way, the carrier of 5.2 GHz is preferentially set when the radio wave intensities of both carriers are substantially equal.
[0057]
If the check box 501 for “prefer higher radio wave intensity” is turned off on the setting screen, a carrier is selected regardless of the radio wave intensity. Therefore, if the check box 503 for “prioritize 5.2 GHz” is set on, the 5.2 GHz is preferentially selected. If the check box 502 for “prioritize 4.9 GHz” is set on, 4.9 GHz is preferentially selected.
[0058]
FIG. 6 is a flowchart showing a carrier selection procedure of the wireless LAN adapter when the 4.9 GHz band and the 5.2 GHz band are simultaneously received.
[0059]
As shown in FIG. 6, when the 4.9 GHz band and the 5.2 GHz band are simultaneously received, the setting information stored in the memory or the like in the wireless LAN adapter is read out (S601), and Based on the selected one carrier.
[0060]
If the setting is such that a carrier having a strong radio wave intensity is selected preferentially (S602Y), the radio wave intensities of both carriers are compared (S603). If one of the radio wave intensities is strong (S603N), the operation is performed to select the stronger one (S604). If the radio wave intensities of both carriers are substantially equal (S603Y), the selection of the carrier based on the radio wave intensity is not performed.
[0061]
When it is not set to preferentially select a carrier having a strong radio wave intensity (S602N), and when it is set to preferentially select a carrier having a strong radio wave intensity, the radio wave intensities of both carriers are substantially equal. In this case (S603Y), it is directly determined whether to select 4.9 GHz or 5.2 GHz based on the setting information (S605).
[0062]
When the setting is such that the carrier of 4.9 GHz is preferentially selected (S605Y), the operation is performed to select the carrier of 4.9 GHz (S606). Therefore, communication with the access point is performed on the carrier in the 4.9 GHz band.
[0063]
If the setting is made such that the 5.2 GHz carrier is selected preferentially (S605N), the operation is performed so as to select the 5.2 GHz carrier (S607). Therefore, communication is performed with the access point using a 5.2 GHz band carrier.
[0064]
As described above, when the 4.9 GHz and 5.2 GHz carriers are simultaneously received, by giving priority to the signal having the stronger radio field intensity, more stable communication with the base station can be realized. Also, by giving priority to the carrier of 4.9 GHz, it is possible to reliably prevent a 5.2 GHz signal restricted to indoor use from being erroneously transmitted outdoors. On the other hand, if priority is given to the carrier of 5.2 GHz, it is possible to provide communication that emphasizes higher speed. Further, when the use of the 4.9 GHz band is a frequency requiring a license or billing and it is desired not to use the frequency as much as possible, 5.2 GHz can be positively used.
[0065]
The present invention is not limited to the embodiments described above, and various changes can be made within the scope of the invention described in the claims, and these are also included in the present invention. Not even.
[0066]
For example, in the above-described embodiment, when a signal of 4.9 GHz and a signal of 5.2 GHz are received at the same time, the one having the highest radio field intensity is preferentially selected, but the radio field intensity is not considered at all. No problem.
[0067]
Further, in the embodiment, from the carrier frequency of the signal transmitted from the base station, it is determined whether the current position is indoors, but is not limited thereto, for example, a frame It is also possible to make the base station transmit a packet including a bit pattern for determining indoors and outdoors, and to receive the packet to make the determination. The frequency at this time may be either 5.2 GHz or 4.9 GHz, but as described above, 4.9 GHz must be used outdoors.
[0068]
Further, in the above-described embodiment, the case where a beacon broadcasted from an access point is used as a signal for determining indoors and outdoors has been described as an example, but the present invention is not limited to this. Any signal can be used as long as the signal can be a special signal.
[0069]
Furthermore, in the above-described embodiment, the case where such a special signal is transmitted from the access point has been described as an example. However, the present invention is not necessarily limited to this case. Other signals may be transmitted. In this case, a special signal used for determining indoors and outdoors is transmitted from the dedicated device, and the wireless terminal device determines whether the current position is indoors from this signal.
[0070]
Further, in the above-described embodiment, an example has been described in which an IEEE 802.11a wireless LAN adapter is applied to a case where one of 5.2 GHz and 4.9 GHz is selected, but the present invention is not limited to this. For example, in a so-called combo type wireless LAN adapter supporting both IEEE 802.11a and IEEE 802.11b, any one of three signals obtained by adding a signal of 2.4 GHz in addition to 5.2 GHz and 4.9 GHz. It may be applied when selecting one. That is, the number of selected frequencies is not limited to two and may be any number.
[0071]
【The invention's effect】
As described above, according to the present invention, a special signal for determining whether or not a current position is indoors is transmitted to a wireless communication device normally used when performing wireless communication with a base station. Since the information is received by the means, the indoor / outdoor determination can be performed without adding a special sensor or circuit.
[0072]
Also, since it is in a standby state until it is determined whether or not it is indoors, the transmission is prohibited, so that it is possible to prevent a situation in which a radio signal of a frequency exclusive for indoors is erroneously transmitted outdoors. it can.
[0073]
Furthermore, based on the determination result by the indoor determination means, the carrier frequency for performing communication with the base station can be automatically set, so that the frequency can be reliably switched according to the current position. Never forget to switch frequencies.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing a configuration of a wireless terminal device according to a preferred embodiment of the present invention.
FIG. 2 is a schematic block diagram illustrating a configuration of a wireless LAN adapter 106.
FIG. 3 is a block diagram illustrating an example of a configuration of an RF unit 204.
FIG. 4 is a flowchart illustrating an example of a carrier selection procedure performed by a wireless LAN adapter.
FIG. 5 is a diagram illustrating an example of a screen for setting a priority of selection of a carrier frequency;
FIG. 6 is a flowchart showing a carrier selection procedure of the wireless LAN adapter when simultaneously receiving the 4.9 GHz band and the 5.2 GHz band.
[Explanation of symbols]
100 wireless terminal device
101 CPU
102 memory
103 Hard Disk Drive (HDD)
104 Removable Media Drive (RMD)
105 Input / output interface (I / O)
106 Wireless LAN Adapter (Wireless Communication Adapter)
107 bus
108 keyboard
109 mouse
110 display
201 Bus interface (I / F)
202 Controller
203 Baseband section (BB section)
204 RF section
205 antenna
206 memory
301 transmission unit
302 RF amplifier
303 Band Pass Filter (BPF)
304 receiver
305 RF amplifier
306 Band Pass Filter (BPF)
307 Transmission / reception switch
308 frequency synthesizer
309 Judgment unit
501 Check box for setting to give priority to the one with stronger signal strength
502 Check box for setting to give priority to “5.2 GHz”
503 Check box for setting to give priority to 4.9 GHz

Claims (11)

Radio communication means for selecting one of a plurality of frequencies including frequencies restricted to indoor use and performing radio communication with the base station,
When the wireless communication unit receives a special signal, comprising an indoor determination unit that determines whether the current position is indoors from the signal,
The wireless communication means,
When the indoor determination unit determines that indoors, to select a frequency restricted to use indoors,
A wireless terminal device, wherein when the indoor determining means determines that the mobile terminal is outdoor, a frequency not restricted to indoor use is selected. The wireless terminal device according to claim 1, wherein the wireless communication unit prohibits transmission until the indoor determination unit determines whether or not the room is indoors. The wireless terminal device according to claim 1, wherein the special signal is a signal transmitted from the base station. The indoor determination means,
If the signal is a frequency restricted to use indoors, determine that the current position is indoors,
4. The wireless terminal device according to claim 1, wherein when the signal has a frequency not restricted to indoor use, the current position is determined to be outdoors. 5. The indoor determination means,
As the signal, when the signal of the frequency restricted to indoor use and the signal of the frequency not restricted to indoor use are received almost simultaneously,
The wireless terminal device according to any one of claims 1 to 4, wherein a signal having the highest radio field intensity is preferentially selected to determine whether the signal is indoors. The indoor determination means,
As the signal, when the signal of the frequency restricted to indoor use and the signal of the frequency not restricted to indoor use are received almost simultaneously,
The wireless terminal device according to any one of claims 1 to 4, wherein a signal of a frequency not restricted to indoor use is preferentially selected to determine whether the signal is indoors. The indoor determination means,
As the signal, when the signal of the frequency restricted to indoor use and the signal of the frequency not restricted to indoor use are received almost simultaneously,
The wireless terminal device according to any one of claims 1 to 4, wherein a signal having a frequency restricted to use indoors is preferentially selected to determine whether the signal is indoors. A wireless communication adapter that provides a wireless communication function to the computer by connecting to the computer,
Radio communication means for selecting one of a plurality of frequencies including frequencies restricted to indoor use and performing radio communication with the base station,
When the wireless communication unit receives a special signal, comprising an indoor determination unit that determines whether the current position is indoors from the signal,
The wireless communication means,
When the indoor determination unit determines that indoors, to select a frequency restricted to use indoors,
A wireless communication adapter, wherein when the indoor judging means judges that it is outdoors, a frequency not restricted to use indoors is selected. Computer with wireless communication function,
Radio communication means for selecting one of a plurality of frequencies including frequencies restricted to indoor use and performing radio communication with the base station,
When the wireless communication unit receives a special signal, comprising an indoor determination unit that determines whether the current position is indoors from the signal,
The wireless communication means,
When the indoor determination unit determines that indoors, to select a frequency restricted to use indoors,
A computer program for functioning as a wireless terminal device that selects a frequency that is not restricted to use indoors when the indoor determination unit determines that the indoor is outdoor. A computer-readable recording medium on which the computer program according to claim 9 is recorded. A method of selecting one from a plurality of frequencies including frequencies restricted to indoor use and performing wireless communication with a base station,
When receiving a special signal, a step of determining whether the current position is indoors from the signal,
When it is determined to be indoors, the method includes a step of selecting a frequency restricted to use indoors, and a step of selecting a frequency not restricted to use indoors when determined to be outdoor. Wireless communication method.

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