JP2012089993A - Wireless communication coexistence system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a high-output device originating a wireless signal with high-output strength, such as a TVWS (Television White Space) or the like, and a low-output device transmitting and receiving a wireless signal with low-output strength coexist without interfering with each other.SOLUTION: When a wide-area wireless communication system in which a wireless signal with high signal strength can be transmitted from a high-output device 11 within a wide-area wireless communication range 10, and a narrow-area wireless communication system located in the wide-area wireless communication range 10, and in which communication by a wireless signal with low signal strength can be performed in a narrow-area wireless communication range 20 narrower than the wide-area wireless communication range 10 by using a low-output device 21, are made coexist, the low output device 21 detects the strength and a signal-to-noise ratio of the received wireless signal. Based on the detection result, the low output device 21 continues the wireless communication in the narrow-area wireless communication range 20, or alternatively stops the wireless communication in the narrow-area wireless communication range 20.

Description

  The present invention relates to a radio communication coexistence system and method suitable for coexistence with a wide area radio communication system capable of transmitting radio signals from a high output device and a narrow area radio communication system capable of radio communication with a low output device.

  Conventionally, standardization of a wireless communication system using TV White Space (TVWS) has been advanced, and in particular, in recent years, standardization of a method (IEEE802.11 standard) for different IEEE802 standards to coexist in TVWS has also been promoted. . For this reason, it becomes particularly important how these different IEEE 802 standard communication systems coexist in the same frequency band, and in particular, the importance has increased with the recent dramatic increase in radio communication opportunities.

  In particular, the TV White Space (TVWS) signal is generally composed of a radio signal having a high signal strength, and is transmitted from a high-power device composed of, for example, a base station, a broadcast station, and other terminals. For this reason, as shown in FIG. 11, when a TVWS signal is transmitted from the high-power device 71, the TVWS signal can be transmitted over a wide area. As a result, the wireless communication range 72 by the TVWS signal becomes wider.

  In such a wireless communication range 72, there may be a low-power device 81 that transmits and receives a wireless signal different from TVWS. The radio signal transmitted / received by the low-power device 81 has a lower strength than that of TVWS. For this reason, the wireless communication range 82 by the low output device 81 is narrower than the wireless communication range 72 described above. There may be a plurality of such low-power devices 81 and a plurality of wireless communication ranges 82 formed thereby.

  At this time, in the case of the arrangement of each device as shown in FIG. 11, the high output device 71 cannot receive the low output intensity wireless signal transmitted from the low output device 81, but the low output device 81 The wireless signal with high output intensity from the high output device 71 can always be received.

  At this time, when the low output device 81 receives a radio signal from another device of the communication partner, the low output device 81 interferes when a high output intensity radio signal such as a TVWS signal from the high output device 71 is transmitted. Will occur.

  Conventionally, various techniques for preventing this interference have been proposed (see, for example, Patent Document 1). However, a technique for preventing communication interference on the low-power device 81 side when the wireless communication range 72 where the TVWS signal is transmitted as shown in FIG. 11 and the wireless communication range 82 by the low-power device 81 coexist. Was not proposed.

JP 2005-529549 A

  Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is to provide a high-power device that transmits a high-power intensity wireless signal such as TVWS, and a low-power device. It is an object of the present invention to provide a wireless communication coexistence system and method capable of coexisting without interfering with each other with a low output device that transmits and receives a wireless signal having an output strength.

  In order to solve the above-described problems, the present inventor detects the strength of a received radio signal and the SN ratio thereof with a low-power device, and based on the detection result, performs radio communication within the above-mentioned narrow area radio communication range. A wireless communication coexistence method capable of preventing communication interference with a high-power device and causing each other's systems to coexist by starting or continuing or stopping wireless communication within the above-mentioned narrow-range wireless communication range Was invented.

  The wireless communication coexistence system according to claim 1 is a wide area wireless communication system capable of transmitting a high signal strength wireless signal from a high power device within a wide area wireless communication range, and is located within the wide area wireless communication range, A narrow-area wireless communication system capable of communicating with a low-signal strength wireless signal by a low-power device in a narrow-area wireless communication range narrower than the communication range, and the low-power device includes the received wireless signal strength and its SN ratio , And based on the detection result, the wireless communication in the narrow wireless communication range is continuously performed, or the wireless communication in the narrow wireless communication range is stopped.

  The wireless communication coexistence system according to claim 2 is the invention according to claim 1, wherein the wireless signal of high signal strength transmitted from the high power device in the wide area wireless communication system is a TVWS (Television White) based on the IEEE 802.11 standard. Space) signal.

  The wireless communication coexistence method according to claim 3 is a wide area wireless communication system capable of transmitting a high signal strength wireless signal from a high output device within a wide area wireless communication range, and is located within the wide area wireless communication range. In a wireless communication coexistence method for coexisting with a narrow-area wireless communication system capable of communicating with a low-signal-intensity wireless signal by a low-power device in a narrow-area wireless communication range narrower than the communication range, the wireless signal received by the low-power device The strength and the SN ratio are detected, and based on the detection result, the wireless communication in the narrow wireless communication range is continuously performed, or the wireless communication in the narrow wireless communication range is stopped. To do.

  According to a fourth aspect of the present invention, there is provided a wireless communication coexistence method according to the third aspect of the present invention, wherein a wireless signal having a high signal strength consisting of a TVWS (Television White Space) signal based on the IEEE 802.11 standard is transmitted in the wide area wireless communication system. It is characterized by transmitting from.

  In this way, in the coexistence communication system to which the present invention is applied, the low-power device detects the strength of the received radio signal and the S / N ratio thereof, and continues the radio communication within the narrow radio communication range based on the detection result. Or wireless communication within the narrow wireless communication range is stopped. Accordingly, the low output device can perform wireless communication with other devices without causing communication interference with the high output device.

It is a block diagram of the coexistence communication system to which this invention is applied. It is a figure for demonstrating the mechanism in which communication interference arises.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  A wireless communication coexistence system to which the present invention is applied is a system in which the IEEE 802 standard is implemented and coexistence processing can be performed in TV White Space (TVWS). However, the communication system to which the present invention is applied is not limited to this, and may be applied in coexistence processing between any other systems in a space other than TVWS.

  As shown in FIG. 1, a coexistence communication system 1 to which the present invention is applied includes a wide area wireless communication system capable of transmitting a high-signal strength wireless signal from a high-power device 11 into a wide area wireless communication range 10, and a wide area wireless communication range. 10 and a narrow area wireless communication system capable of communicating with a low signal strength wireless signal by a low output device 21 in a narrow area wireless communication range 20 narrower than the wide area wireless communication range 10.

  The high output device 11 may be configured by a device such as a PC (personal computer) or various portable communication terminals, but may be a base station, a control station, or the like. The high-power device 11 transmits a radio signal having a high signal strength such as a TVWS signal. For this reason, the radio signal transmitted from the high output device 11 reaches the low output device 21 over a wide range. In other words, since the radio signal transmitted from the high-power device 11 has a high signal strength, the wide area radio communication range 10 is widened.

  The low output device 21 is various terminals such as a mobile phone and a personal computer (PC). The low output device 21 transmits and receives wireless signals with low output intensity other than the TVWS signal to and from other low output devices 21. That is, since the radio signal transmitted from the low-power device 21 has low signal strength, the narrow area radio communication range 20 becomes narrower.

  Such a low-power device 21 can receive a radio signal having a high signal intensity transmitted from the high-power device 11, but in the case of the arrangement shown in FIG. A low signal strength radio signal transmitted from the output device 21 cannot be received.

  For this reason, when the low-power device 21 communicates with other devices within the narrow-band wireless communication range 20, the high-power device 11 transmits a wireless signal having a high output strength such as a TVWS signal. In some cases, interference will occur.

  Therefore, in the present invention, on the low-power device 21 side, processing operation is performed so that communication interference with the high-power device 11 does not occur and the mutual systems can coexist. .

  When performing such processing operation, the low-power device 21 first determines whether or not the wireless signal from the high-power device 11 can be received. In this determination process, first, the strength of the received radio signal and its SN ratio are detected.

  The low output device 21 may make a determination as shown in Table 1 below based on the intensity of the wireless signal and the detection result of the SN ratio.

  Incidentally, in Table 1, whether the signal strength and the SN ratio are high or low may be determined based on whether a threshold value is set in advance for each of the signal strength and the SN ratio, for example.

  When the signal strength of the detected radio signal is high and the SN ratio is also high, it is determined that a high-quality signal has been received. This means that the low-power device 21 can receive a high-quality wireless signal from another low-power device 21 without causing communication interference based on the wireless signal from the high-power device 11. In such a case, since the low-power device 21 is not particularly in a state of receiving a wireless signal from the high-power device 11, wireless communication is continuously performed.

  When the signal strength of the detected radio signal is high and the signal-to-noise ratio is low, in addition to being able to receive the radio signal that the low-power device 21 actually wants to communicate with, it actually wants to communicate. This means that no radio signal is being received. Here, the radio signal that the low-power device 21 desires to communicate is another low-power device 21 in the narrow-band radio communication range 20. The wireless signal that the low output device 21 does not wish to communicate with is a high signal strength wireless signal transmitted from the high output device 11.

  In such a case, the low-power device 21 determines that communication interference has occurred. And when it determines with this communication interference having arisen, the low output device 21 stops the radio | wireless communication in the own narrow area | region radio | wireless communication range 20. FIG. As a result, it is possible to prevent communication interference.

  Furthermore, when the signal strength of the detected radio signal is low and the signal-to-noise ratio is low, the low-power device 21 has not received any signal. In such a case, the low-power device 21 does not perform any special operation before receiving a new signal without performing wireless communication.

  The low output device 21 performs the above-described processing based on a program stored in itself.

  Thus, in the coexistence communication system 1 to which the present invention is applied, the low-power device 21 detects the strength of the received radio signal and the SN ratio thereof, and performs radio communication within the narrow area radio communication range based on the detection result. The wireless communication within the narrow area wireless communication range 20 is stopped. Thereby, the low output device 21 can perform wireless communication with other devices without causing communication interference with the high output device 11 in particular.

  When the low-power device 11 detects the intensity of the received radio signal and the S / N ratio thereof, the above-described determination may be performed by another device (not shown). In such a case, the low-power device 11 makes a request to another device (not shown) to request the determination, and when there is an approval response to the request, the low-power device 11 determines the strength of the received radio signal and its SN ratio. Send to another device (not shown). Next, another device (not shown) performs the above-described determination based on the strength of the received radio signal and the SN ratio, and transmits the determination result to the low-power device 11.

  Note that the high signal strength wireless signal transmitted from the high output device 11 in the wide area wireless communication system is assumed to be a TVWS signal based on the IEEE 802.11 standard, but is not limited to this. Of course, any standard signal may be used as long as it transmits a radio signal having a higher signal strength than the low-power device 21 and has a wider communication range than the narrow-band radio communication range 20.

DESCRIPTION OF SYMBOLS 1 Coexistence communication system 10 Wide area wireless communication range 11 High output device 20 Narrow area wireless communication range 21 Low output device

Claims (4)

A wide area wireless communication system capable of transmitting a high signal strength wireless signal from a high output device within a wide area wireless communication range;
A narrow area wireless communication system that is located within the wide area wireless communication range and is capable of communicating with a low signal strength wireless signal by a low output device in a narrow area wireless communication range narrower than the wide area wireless communication range;
The low power device detects the strength of the received radio signal and the SN ratio thereof, and continuously performs radio communication within the narrow radio communication range based on the detection result, or the narrow radio communication range. Wireless communication coexistence system characterized by stopping wireless communication within the network. 2. The wireless communication coexistence system according to claim 1, wherein the high-signal-intensity wireless signal transmitted from the high-power device in the wide-area wireless communication system is a TVWS (Television White Space) signal based on the IEEE 802.11 standard. . In a wide area wireless communication system capable of transmitting a high signal strength wireless signal from a high output device within a wide area wireless communication range, and in a narrow area wireless communication range that is located within the wide area wireless communication range and narrower than the wide area wireless communication range In a wireless communication coexistence method that coexists with a narrowband wireless communication system capable of communicating with a low signal strength wireless signal by a low output device,
The low-power device detects the strength of the received radio signal and the S / N ratio thereof, and continuously performs radio communication within the narrow-band radio communication range based on the detection result, or the narrow-band radio communication range Wireless communication coexistence method characterized by stopping wireless communication within the network. 4. The wireless communication coexistence method according to claim 3, wherein a high-signal-intensity wireless signal composed of a TVWS (Television White Space) signal based on the IEEE 802.11 standard is transmitted from a high-power device in the wide-area wireless communication system.

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