KR101599700B1 - Frequency control apparatus of wireless communication apparatus using TV white space and method therefor - Google Patents

Abstract

An apparatus and method for controlling a frequency of a wireless communication apparatus using a TV white space according to an embodiment of the present invention includes: detecting an existing user apparatus located in a super Wi-Fi service area using a white space; And checking the occupied band used by the existing user equipment in the white space, and using the remaining band, which is the remaining band excluding the occupied band, as a control channel.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency control apparatus for a wireless communication apparatus using a white space,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for controlling a frequency of a wireless communication apparatus using a TV white space, and more particularly to a wireless data communication system using a TV white space and a wireless data communication system using a white space such as a super WiFi A wireless communication using a TV white space that enables rapid service management of an access point (AP) and a terminal channel by using, as a control channel, a residual band that is not affected by an occupied band of an existing user apparatus in an operating data channel band To a frequency control apparatus and a method thereof.

Worldwide, frequency bands ranging from tens MHz to about 900 MHz are allocated for terrestrial TV broadcasting, and TV channel frequency allocation standards are set according to the broadcasting environment of each country and are in use. This TV band has an advantage that the transmission characteristic is superior to the frequency band of 1 GHz or more that is currently used for wireless communication due to its low propagation attenuation characteristic. In this frequency band, the band that is not used by broadcasters and the frequency band that is vacant at the time when broadcasting is not transmitted is called TV white space.

The US Federal Communications Commission (FCC) has approved the use of wireless communication devices by applying cognitive radio (CR) technology, a frequency sharing technology, to allow the introduction of new information and communications services in the TV white space bands. In particular, the FCC defines the new wireless Internet service technology that constitutes WiFi network using TV white space as super WiFi name. This technology is expected to spread as a key technology in wireless communication networks that seamlessly cover urban areas and suburbs in the future.

A wireless communication device system using a TV white space band such as super Wi-Fi is a prerequisite that an incumbent user device such as a wireless microphone should preferentially yield a frequency band required by an existing user device when appearing in the band . Wireless cognitive technologies such as spectrum sensing technology are being used to meet the utilization constraints of such TV white space.

According to IEEE 802.11af, a super Wi-Fi standard, when an existing user equipment appears in an active band of an active super Wi-Fi device, it has to give up a frequency band corresponding to one TV channel transmission band of 6 MHz. When a Super WiFi device that is interrupted due to a concession of bandwidth tries to resume a service that was in progress, the bandwidth in the TV white space that can be used is searched for every 6 MHz, and the bandwidth required for wireless communication is secured to resume communication .

A typical conventional user device using a TV white space is a wireless microphone occupying a bandwidth of about 200 kHz. Even if the bandwidth of the existing user equipment is much smaller than 6MHz, if such a device appears in the operating band of the Super WiFi system in operation, the user can concede the bandwidth in 6MHz band and then use the 6MHz You have to find the band and configure a new radio channel. These procedures include sensing of existing user equipment, available TV white space spectrum sensing, setting up a new wireless channel, sharing an access point (AP) with established terminal and wireless channel information, sharing wireless data with a new wireless channel The process of resuming communication should be done in order, and the AP of the super Wi-Fi system handles these procedures exclusively.

There is a problem that the service control between the AP and the terminal is interrupted because the normal use of the data communication channel of the super Wi-Fi system becomes impossible when the existing user equipment appears between the AP and the terminal of the super Wi-Fi system in service. The control channel between the AP and the terminal is indispensable for notifying the service stop due to the appearance of the existing user equipment and for exchanging information of a new frequency band for service resumption.

As a method of constructing a control channel lost by the appearance of an existing user equipment, there is a method of constructing a separate control channel in a TV white space whenever necessary or configuring a control channel by setting a specific frequency band in advance. The method of constructing the control channel whenever necessary is complicated in that the process of finding the available frequency band in the TV white space and sharing the control channel information between the AP and the terminal and starting the communication is complicated, Other existing user devices may cause failures. A method of constructing a control channel for a specific frequency band requires a separate frequency band to be used only for the control channel, which increases the cost.

Therefore, there is a need for a method to manage the service by configuring the control channel between the AP and the terminal quickly without requiring a separate frequency band when the service is stopped due to the appearance of the existing user device in the super Wi-Fi system in service Do.

The present invention utilizes a residual bandwidth that is not affected by an existing user apparatus in a data channel band used in a wireless communication system using a TV white space as a control channel, thereby quickly transmitting / receiving control information between the AP and the terminal And a method for controlling the frequency of a radio communication apparatus using a white space, which can be used in a radio communication system, and a method thereof.

In addition, the present invention can speed up the service management between the AP and the terminal due to the quick control channel configuration, thereby improving the service quality, and the data service interrupted by the appearance of the existing user equipment using the rapidly configured control channel The present invention provides a frequency control apparatus and method for a wireless communication apparatus using a TV whitespace in which information on an available frequency band in a newly found TV white space can be immediately shared between an AP and a terminal .

In addition, the present invention manages and utilizes the TV white space band in a sub-band which is smaller than the TV channel band, thereby enhancing the utilization efficiency of the TV white space band and making it possible to find in a neighboring frequency band Which can reduce the RF band of the super Wi-Fi system, thereby reducing the requirement for hardware performance, and a method for controlling the frequency of the wireless communication apparatus.

A network communication method using a TV white space according to an embodiment of the present invention includes: detecting an existing user device located in a super Wi-Fi service area using a white space; And checking the occupied band used by the existing user equipment in the white space, and using the remaining band, which is the remaining band excluding the occupied band, as a control channel.

According to the apparatus and method for controlling a frequency of a wireless communication apparatus using a TV whitespace according to an embodiment of the present invention, when a conventional user apparatus appears in a data channel band used in a wireless communication system using a TV white space, It is possible to quickly transmit / receive control information between the AP and the terminal by utilizing the remaining band as a control channel.

In addition, since the service management between the AP and the UE can be performed quickly by configuring the control channel quickly without configuring a separate control channel, the quality of service can be improved and the existing user equipment In order to resume the suspended data service, it is possible to instantly share information about the available frequency bands within the newly discovered TV whitespace between the AP and the terminal, thereby enabling quick service resumption.

In addition, by managing and using the TV white space band in a sub-band having a smaller size than the TV channel band, it is possible to increase the utilization efficiency of the TV white space band and increase the possibility of finding the band in the neighboring frequency band The RF bandwidth of the super Wi-Fi system can be narrowed, which can alleviate hardware performance requirements.

1 is a diagram showing a configuration example of a general super Wi-Fi system.
FIG. 2 is a diagram illustrating a correspondence of a super Wi-Fi system when an existing user device capable of interfering with an operating super Wi-Fi system is detected according to an embodiment of the present invention.
3 is a diagram illustrating a configuration of an AP according to an embodiment of the present invention.
4 is a diagram illustrating a frequency division scheme for a TV white space band according to an embodiment of the present invention.
5 is a diagram illustrating a frequency band when an existing user apparatus is detected in a TV white space band according to an embodiment of the present invention.
6 is a diagram illustrating a network communication method using a TV white space according to an embodiment of the present invention.
FIG. 7 shows a procedure of a signal transmitted between the AP and the terminal in the process of FIG.
8 is a diagram illustrating a network communication method using a TV white space according to another embodiment of the present invention.
9 shows a procedure of a signal transmitted between the AP and the terminal in the process of FIG.
10 is a diagram illustrating a method of forming a control channel between an AP and a terminal and transmitting and receiving a control signal according to an embodiment of the present invention.
11 illustrates a data format of a sub-carrier forming a control channel between an AP and a UE according to an embodiment of the present invention.
12 shows an example of a message format when conveying alternate carrier frequency information according to an embodiment of the present invention.

It is noted that the technical terms used in the present invention are used only to describe specific embodiments and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be construed in a sense generally understood by a person having ordinary skill in the art to which the present invention belongs, unless otherwise defined in the present invention, Should not be construed to mean, or be interpreted in an excessively reduced sense. In addition, when a technical term used in the present invention is an erroneous technical term that does not accurately express the concept of the present invention, it should be understood that technical terms can be understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

Furthermore, the singular expressions used in the present invention include plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as "comprising" or "comprising" and the like should not be construed as encompassing various elements or various steps of the invention, Or may further include additional components or steps.

Furthermore, terms including ordinals such as first, second, etc. used in the present invention can be used to describe elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or similar elements throughout the several views, and redundant description thereof will be omitted.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

1 is a diagram showing a configuration example of a general super Wi-Fi system. As shown, a typical super Wi-Fi system may include an AP 110, a first terminal 120, and a second terminal 130 using a TV white space 140.

The AP 110 stores band information of the TV white space 140 on the basis of the TV broadcast channel information according to the installation area and checks the available frequency band when communication with the terminals 120 and 130 is required. Information can be shared with the terminals 120 and 130.

Accordingly, a wireless data channel can be established between the AP 110 and the terminals 120 and 130 and data communication can be performed.

Examples of the terminals 120 and 130 include a smart phone, a notebook, a tablet PC, and a computer.

FIG. 2 is a diagram illustrating a correspondence of a super Wi-Fi system when an existing user device capable of interfering with an operating super Wi-Fi system is detected according to an embodiment of the present invention.

As shown, when a first existing user equipment 210, which may interfere with the super Wi-Fi system, starts operating within a super Wi-Fi coverage area determined by the AP 110, And notifies the terminals 120 and 130 that the current use of the TV white space 140 is temporarily disabled, and stops the service in progress.

In addition, when the second terminal 130 detects a second existing user equipment 220 located outside the super Wi-Fi service area, the second terminal 130 transmits this fact to the AP 110, 110 stops temporarily the service in progress and if the service is continuously needed, the TV searches for and confirms a usable frequency band among the white space 140 bands to configure a wireless channel, It is possible to resume the communication service after setting the wireless channel between the AP 110 and the terminals 120,

3 is a diagram illustrating a configuration of an AP according to an embodiment of the present invention. The AP 110 according to an embodiment of the present invention may include a communication unit 111, a sensing unit 112, a channel searching unit 113, and a controller 114.

Not all of the components of the AP shown in Fig. 3 are required components, and the APs may be implemented by more components than the components shown in Fig. 3, or APs may be implemented by fewer components .

The communication unit 111 can perform data communication with a terminal located in the super Wi-Fi area determined by the AP 110. [

The sensing unit 112 may sense a terminal located in a super Wi-Fi area determined by the AP 110 and an existing user equipment.

The channel searching unit 113 detects the existing user equipment located in the super Wi-Fi area determined by the AP 110, the remaining band 430 (see FIG. 5) other than the occupied band 420 : See Fig. 5).

The control unit 114 may control the overall functions related to the operation of the AP 110, for example, operations related to channel setting, service stop and resume.

4 is a diagram illustrating a frequency division scheme for a TV white space band according to an embodiment of the present invention. As shown, the TV white space is subdivided in units of DELTA f, and each subband is divided into DELTA fi (i = 1, 2, 3, ...) and managed by the AP 110. [ If the total usable white space of the white space is W, the number of small bands is W /? F.

5 is a diagram illustrating a frequency band when an existing user apparatus is detected in a TV white space band according to an embodiment of the present invention. When the existing user equipment appears in the white space band in use by the existing user equipment and the existing user equipment uses the occupation band 420 among the utilization band 410 of the super Wi-Fi system, the remaining band 430, which is the remaining band excluding the occupied band, It is used as a control channel.

6 is a diagram illustrating a network communication method using a TV white space according to an embodiment of the present invention.

As shown, the AP detects an existing user device located in the super Wi-Fi service area (S110). Next, the occupied bandwidth used by the existing user apparatus is confirmed (S120). Next, when the existing user equipment uses occupied bandwidth among the available bandwidth of the super Wi-Fi system, the AP uses the remaining bandwidth, which is the remaining bandwidth excluding the occupied bandwidth, as the control channel to notify the terminal in the service area that the service is stopped S130). Next, a new data channel is acquired through frequency band search in the TV white space (S140). Next, the newly secured data channel is notified to the terminal in the service area using the control channel (S150). Next, the suspended data communication is resumed between the AP and the terminal using the new data channel (S160).

FIG. 7 shows a procedure of a signal transmitted between the AP and the terminal in the process of FIG. First, as shown, the AP detects an existing user device located in the super Wi-Fi service area. Next, stop the ongoing service and check the occupied bandwidth used by the existing user equipment. Next, using the remaining bandwidth, which is the remaining bandwidth excluding the bandwidth occupied by the existing user equipment, among the available bandwidth of the super Wi-Fi system as a control channel, it notifies the terminal in the service area that the service is stopped. Next, the AP identifies the new frequency band through data channel replacement. Next, alternative data channel information is transmitted to the UE using the control channel. Next, the terminal confirms the alternative data channel.

8 is a diagram illustrating a network communication method using a TV white space according to another embodiment of the present invention. Unlike FIG. 6, a case where a terminal located in a super Wi-Fi service area detects an existing user apparatus is described as an example.

First, the terminal detects an existing user apparatus (S210). Next, the terminal checks the occupied bandwidth used by the existing user apparatus (S220). Next, the AP and the occupied band of the existing user device are informed to the AP using the control channel (S230). Next, the AP informs the terminal in the service area of the service stop using the control channel (S240), secures the alternative data channel in the AP, and resumes the data communication (S250).

9 shows a procedure of a signal transmitted between the AP and the terminal in the process of FIG. In order, first, a specific terminal detects an existing user apparatus as shown in the figure. Next, the terminal stops the ongoing service and checks the occupied bandwidth used by the existing user equipment. Next, when a control channel is formed and the AP notifies the AP of the stop of the service, the AP informs the other terminal of the stop of the service through the control channel. Next, the AP confirms a new frequency band for data channel replacement, transmits the alternative data channel information to each terminal through the control channel, and resumes communication service.

10 is a diagram illustrating a method of forming a control channel between an AP and a terminal and transmitting and receiving a control signal according to an embodiment of the present invention.

The AP 110 or the terminals 120 and 130 of the super Wi-Fi system, which is subdivided into a predetermined frequency unit within one channel band and uses the TV white space, transmits the OFDM carrier wave (930).

10, the total number of OFDM carriers fsc constituting the data channel of the super Wi-Fi system is m, and the carrier frequencies that can not be used due to band occupancy of the existing user equipments 210 and 220 are fsc, k + 1, 1 to fsc, k and fsc, l to fsc, m, and the carrier frequencies located in the residual bands 910 and 920 are denoted by fsc, .

Is applied to a super WiFi using the TV white space of the present invention, and FIG. 10 is shown for explaining an example, and the present invention is not limited to the OFDM scheme. That is, the technical idea of the present invention can be applied to other transmission systems.

11 illustrates a data format of a sub-carrier forming a control channel between an AP and a UE according to an embodiment of the present invention.

When the AP 110 or the terminals 120 and 130 in operation in the super Wi-Fi service detect the existing user devices 210 and 220, the service data transmission is stopped and the carrier channels corresponding to the residual bands 910 and 920 And transmits a certain number of consecutive '1' data 810 through the control channel.

That is, when the first existing user equipment 210 is detected by the AP 110, a predetermined number of '1' data 810 is transmitted to the terminals 120 and 130, When a second existing user equipment 220 is detected by the second terminal 130, a predetermined number of '1' data 810 is transmitted to the AP 110 to continuously receive '1' It is confirmed that the counterpart apparatus has detected the existing user apparatuses 210 and 220.

Accordingly, the AP 110 and the terminals 120 and 130 complete the process of notifying the detection of the existing user devices 210 and 220 to each other and checking the control channel.

FIG. 12 shows an example of a message format when conveying alternate carrier frequency information according to an embodiment of the present invention. Specifically, it may include a header, a transmitting apparatus address, a receiving apparatus address, and alternative carrier frequency information.

As described above, by using the residual band that is not affected by the existing user apparatus in the data channel band being used in the wireless communication system using the TV white space as the control channel, information on the available frequency band in the TV white space is transmitted to the AP So that the service can be restarted quickly.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents thereof should be construed as falling within the scope of the present invention.

110: access point
120:
130:
140: TV White Space
210: a first existing user device
220: second existing user device
420: Occupied band
430: Residual band

Claims (8)

Dividing a white space of a TV into small bands (? F) of a predetermined frequency unit and managing by an AP (Access Point);
Detecting an existing user device located in a super Wi-Fi service area using a white space;
Confirming an occupied band used in the white space by the existing user equipment and notifying a terminal in the service area of the service stop using the remaining band as the remaining band excluding the occupied band as a control channel;
Acquiring a new data channel through a frequency band search in a TV white space; And
And notifying the terminal in the service area of the new data channel using the control channel and resuming the suspended data communication between the AP and the terminal through the new data channel. Wherein the frequency of the radio communication apparatus is set to a predetermined frequency.
The method according to claim 1,
If one of an access point (AP) or a terminal using the super Wi-Fi detects the existing user equipment, transmitting data to the other through a control channel corresponding to the residual band range to inform that the existing user equipment is detected; Wherein the frequency of the frequency band of the wireless communication apparatus is set to a predetermined frequency.
delete The access point (AP) manages the white space of the TV in an OFDM-based super Wi-Fi system by dividing the white space into small bands (? F) of a predetermined frequency unit;
Detecting an existing user device located in a super Wi-Fi service area using a white space;
Notifying a terminal in a service area of a service stop using a carrier frequency located in a residual band range not used by the existing user equipment as a control channel;
Acquiring a new data channel through a frequency band search in a TV white space; And
And notifying the terminal in the service area of the new data channel using the control channel and resuming the suspended data communication between the AP and the terminal through the new data channel. Wherein the frequency of the radio communication apparatus is set to a predetermined frequency.
5. The method of claim 4,
And transmitting the data to the other user through the control channel corresponding to the residual band range when one of the AP or the terminal using the super WiFi detects the existing user equipment to inform that the existing user equipment is detected Wherein the white space is a white space.
6. The method of claim 5,
Wherein the data transmission / reception is performed by transmitting / receiving predetermined characters.
6. The method of claim 5,
And notifying the terminal of the alternative carrier information identified by the AP using the carrier control channel of the residual band.
delete

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