JP6213909B2 - The database - Google Patents

Description

  The present invention relates to a database for storing information and providing the same to the outside, and more particularly, to a database for providing information relating to a television white space (TVWS) to a wireless communication device.

  A wireless communication standard that uses the same frequency band as that of licensed television broadcasting and can be operated without a license is being studied. In these standards, a TV user is a primary user, and only when the licensed frequency band of the primary user is not used, the secondary user is allowed to use the frequency band (unused licensed frequency band = white space). Allow to operate wireless communication.

  The secondary user communication device used in such an environment queries its dedicated database, for example, for the TV channel to confirm that no TV signal is present. That is, the current position information of the communication device is transmitted to the database, and a list of frequencies that can be used (effective) at the position is obtained from the database. Then, a frequency to be used is selected from the frequencies in the list, and wireless communication is performed as a secondary user.

  This database is roughly as follows, for example. That is, the geographical area to be protected is calculated using data relating to the primary user such as the location of the transmitting station used by the primary user, transmission power, and channel (frequency). This is performed for all primary users, and the calculation results are stored in a database.

  In calculating the geographical area to be protected, the processing load on the database increases although the calculation becomes more accurate if terrain data is taken into consideration. If the accuracy is insufficient, the geographical area is calculated to be larger from the viewpoint of the primary user protection. This is a state where it cannot be said that the frequency band can be effectively utilized from the secondary user side.

  On the other hand, for effective use of the frequency band, there may be a database that responds to inquiries from secondary users by calculating the allowable transmission output (reduction output) along with the frequencies that can be used at that location. Yes. This allows fine secondary use, but increases the database processing burden and may require a high processing speed for quick answers.

FCC, “Second report and order and memorandum opinion and order, in the matter of unlicensed operation in the tv broadcast bands additional spectrum for unlicensed devices below 900 mhz and in the 3 ghz band (fcc 08-260)”, Nov.2008. OFCOM, “Consultation document: Digital dividend -cognitive access”, February 2009. FCC, “Second memorandum opinion and order (fcc 10-174)”, September 2010. Gabriel Porto Villardi and Hiroshi Harada, “Computer Prediction of Broadcast Contour and Service Areas for VHF / UHF Unlicensed White-Space Radio Systems”, IEICE Technical Report, SR2012-33 (2012-07), pp. 87-92, Jul. 2012 .

  The present invention provides a database for providing information on a television white space to a wireless communication device, and a database capable of responding promptly to providing highly accurate and detailed information while reducing the processing load as a database. The purpose is to provide.

  In order to solve the above-described problem, the database according to one aspect of the present invention is configured such that a point at a predetermined distance from the center of each of the radiation paths centering on the transmission antenna position of the primary user is adjacent. Means for storing and retaining the primary user's protected area boundary based on a first geographic figure that is a connected and represented geographic figure for all pairs of radiation paths; and The interference intensity caused by the maximum output radio wave emitted by the secondary user equipment that is received by the primary user receiver located at the position intersecting with the geographical figure and separated from the primary user receiver by a distance on the extension line of the radiation path is predetermined. The position of the secondary user equipment that becomes the threshold is calculated as a white space available geographical boundary point based on the radio wave propagation conditions from the secondary user equipment to the primary user receiver. And an operable region boundary relating to the secondary user equipment based on a second geographical shape which is a geographical shape obtained by connecting the white space available geographical boundary points to all pairs of the adjacent radial paths. Can be operated if the current location of the secondary user equipment is outside the operable area boundary when an inquiry about the white space is made from the secondary user equipment that is intended to start operation. And a means for sending a reply to the secondary user device that the operation is not possible if the current location of the secondary user device is inside the operable region boundary.

  ADVANTAGE OF THE INVENTION According to this invention, in the database for providing the information regarding a television white space to a radio | wireless communication apparatus, it can respond to providing a highly accurate and detailed information rapidly, reducing a processing burden as a database. .

The functional block diagram which shows the structure of the database which is one Embodiment. The schematic diagram for demonstrating the functional operation | movement of the uniform distance calculation part 11 shown in FIG. The schematic diagram for demonstrating the function operation | movement of the test target position received intensity | strength calculation part 13 shown in FIG. Explanatory drawing which shows the 1st geographic figure which is a specific result by the test object position received intensity | strength calculation part 13 and the threshold value comparison part 15 shown in FIG. The schematic diagram for demonstrating the function operation | movement of the white space useable geographical boundary point calculation part 22 shown in FIG. Explanatory drawing which shows the 2nd geographic figure which is a specific result by the white space useable geographical boundary point calculation part 22 shown in FIG. FIG. 3 is an explanatory diagram schematically illustrating an operable area boundary held by an operable area boundary storage holding unit shown in FIG. 1; Explanatory drawing which shows the 3rd geographic figure which is another specific result by the white space useable geographical boundary point calculation part 22 shown in FIG. FIG. 3 is an explanatory diagram illustrating the contents of specific information related to an operable area boundary held by an operable area boundary storage holding unit shown in FIG. 1; The functional block diagram which shows the structure of the database which is another embodiment. The schematic diagram for demonstrating the functional operation | movement of the primary user receiver receiving strength calculation part 31 and the primary user receiver disturbance strength calculating part 33 shown in FIG. The schematic diagram for demonstrating the new operation possible area | region which can be added by the function operation demonstrated in FIG. Explanatory drawing which shows the new operation | use possible area | region shown in FIG. The schematic diagram for demonstrating the functional operation | movement of the primary user receiver reception intensity | strength calculation part 31 shown in FIG. 10 different from what was shown in FIG. The schematic diagram for demonstrating the functional operation | movement of the primary user receiver disturbance intensity | strength calculation part 33 shown in FIG. 10 different from what was shown in FIG.

  As an embodiment of the present invention, when calculating the white space usable geographical boundary point, in addition to calculating the white space usable geographical boundary point, the secondary user equipment is a reduced radio wave whose power is lower than the maximum output radio wave. The secondary user equipment position at which the interference intensity received by the primary user receiver becomes the threshold value is calculated as a second type white space available geographical boundary point, and the second type white space Based on the third geographic figure, which is a geographic figure represented by connecting the available geographic boundary points for all pairs of the adjacent radial paths, the second type operational area boundary for the secondary user equipment is stored. When an inquiry about white space is made from the holding means and the secondary user equipment that is going to start operation, the current position of the secondary user equipment is If it is outside the usable area boundary, a reply indicating that it can be operated with the maximum output radio wave is sent, and the current position of the secondary user equipment is inside the operational area boundary and the second type operational area boundary. If the current position of the secondary user device is inside the boundary of the second type operational area, the reply indicating that the operation is impossible is performed. And a means for sending to the secondary user equipment.

  This mode is an example of a configuration for providing detailed information. That is, according to this, the operable area boundary that can be operated with the maximum output radio wave and the second type operable area boundary that can be operated with the reduced radio wave are calculated. An answer can be given that it can be operated with reduced radio waves depending on the location. In this case, the situation where the frequency band is effectively used is promoted. The calculation of the second type operable area boundary can be performed in the same procedure as the calculation of the operable area boundary as described above, and the processing complexity is not particularly increased. It is also possible to classify the reduced radio waves more finely and calculate the second type operable area boundary for each class. This makes it possible to provide more detailed information.

  Further, as an embodiment, in each of the radiation paths, the primary user receiver in the primary user receiver at the inspection target position that is a position on the radiation path that is closer to the transmission antenna position than the white space available geographical boundary point. Means for calculating reception intensity from a user based on radio wave propagation conditions from the position of the transmission antenna to the primary user receiver, and reception of a primary user at a predetermined distance from the inspection target position on the radiation path; Means for estimating the interference intensity caused by the radio wave emitted by the secondary user equipment at the inspection target position on the radiation path received by the machine based on the radio wave propagation conditions from the secondary user equipment to the primary user receiver; The transmission power generated by the secondary user equipment whose difference between the reception strength and the interference strength becomes a predetermined threshold is calculated as the allowable transmission power. And when the secondary user equipment that is about to start operation is inquired about the white space, if the current position of the secondary user equipment is effectively at the same position as the inspection target position on the radiation path And a means for sending a reply to the effect that the operation is possible within the range of the allowable transmission power to the secondary user device.

  This aspect is another configuration example for providing detailed information. According to this aspect, even within the primary user's protected area boundary, white space can be found under the condition that the primary user receiver is not significantly disturbed. Therefore, the situation where the frequency band is effectively used further increases. In this aspect, the allowable transmission power of the secondary user equipment is determined under the condition that no significant interference is caused to the primary user receiver within a predetermined distance from the secondary user equipment.

  Further, as an embodiment, in each of the radiation paths, in the first primary user receiver at the inspection target position that is a position on the radiation path closer to the transmission antenna position than the white space available geographical boundary point, Means for calculating the reception intensity from the primary user based on radio wave propagation conditions from the transmitting antenna position to the first primary user receiver; and a known distance from the inspection target position on the radiation path A first disturbance intensity, which is a disturbance intensity caused by a radio wave emitted by the secondary user equipment at the position to be inspected on the radiation path, received by the second primary user receiver at the position is transmitted from the secondary user equipment. Means for estimating based on radio wave propagation conditions up to the second primary user receiver, and the difference between the signal strength and the first interference strength becomes a predetermined threshold value. Means for calculating the transmission power emitted by the user equipment as a first allowable transmission power, and a third primary user receiver located at another known distance away from the inspection target position on the radiation path; The second interference intensity, which is the interference intensity due to the radio wave emitted by the secondary user equipment at the inspection target position on the radiation path, is defined as a radio wave propagation condition from the secondary user equipment to the third primary user receiver. Means for estimating based on the transmission power generated by the secondary user equipment, wherein the difference between the signal strength and the second interference strength is the predetermined threshold value, and a second allowable transmission power, Information indicating whether or not the second primary user receiver and the third primary user receiver are used is indicated by the second primary user receiver and the third primary user receiver. Karaso When the inquiry about the white space is made from the means for acquiring the secondary user equipment and the secondary user equipment to start operation, the current position of the secondary user equipment is effectively the same position as the inspection target position on the radiation path. And when the information that neither the second primary user receiver nor the third primary user receiver is used is acquired, it can be operated within a predetermined allowable transmission power range. If the current position of the secondary user equipment is effectively at the same position as the inspection target position on the radiation path and the second primary user receiver is used, When the information indicating that the primary user receiver is not used is acquired, a response indicating that the primary user receiver is operable within the range of the first allowable transmission power is sent as the current location of the secondary user equipment. Before on the radiation path When information indicating that the second primary user receiver is not used and the third primary user receiver is used is effectively located at the same position as the inspection target position , A response indicating that the second user equipment can be operated within the range of the second allowable transmission power is that the current position of the secondary user equipment is effectively at the same position as the inspection target position on the radiation path and the second Less than one of the first and second permissible transmission powers when information indicating that both the first primary user receiver and the third primary user receiver are used is acquired. And a means for sending a reply indicating that the operation is possible within the range of the allowable transmission power of the other to the secondary user device.

  This aspect is another configuration example for providing detailed information. Again, white space can be found within the primary user's protected area boundary, provided that the primary user receiver is not significantly disturbed. Therefore, the situation where the frequency band is effectively used further increases. In this aspect, more specifically, any of the primary user receivers (not limited to two or more) that are actually used (viewed) at a known distance from the secondary user equipment. The allowable transmission power of the secondary user equipment is determined under the condition that no significant interference occurs. Therefore, there is means for acquiring information as to whether or not the primary user receiver is actually viewed. If the primary user receiver is moved and used, a means for acquiring the position information is provided so that the distance from the secondary user device is obtained and used for estimating the interference intensity. Like that.

  Further, as an embodiment, as a first means for calculating the first geographic figure, a separation distance from the transmission antenna position at which a reception intensity from the primary user becomes a predetermined threshold value, Based on the radio wave propagation conditions excluding topographic data from the transmitting antenna position, as a means for calculating a uniform distance not depending on the direction, and as a second means for calculating the first geographic figure, each of the radiation paths And applying a position gradually approaching the transmission antenna position with an initial value at a position away from the transmission antenna position based on a radio wave propagation condition including terrain data from the transmission antenna position. A means for calculating the received intensity from the position as the inspection target position received intensity, and a third means for calculating the first geographic figure, the inspection As a means for determining whether or not an elephant position reception intensity exceeds the predetermined threshold value and a fourth means for calculating the first geographic figure, the inspection target position reception intensity is the threshold value for the first time. The position from the transmitting antenna applied immediately before the position from the transmitting antenna that calculated the inspection target position received intensity is more than the predetermined distance in the first geographic figure. And a means for setting as a position.

  This aspect is a more specific configuration for calculating the first geographic figure in obtaining the protected area boundary of the primary user. According to this configuration, the terrain data is also utilized, so that the accuracy of calculation is improved. Also, applying the position gradually approaching the transmitting antenna position, with the initial value being a point at a uniform distance from the transmitting antenna position, calculated without considering the topographic data, the received intensity of the inspection target position falls below a predetermined threshold value. Therefore, it is possible to suppress the calculation amount (processing load) as a whole. This is because the position at which the inspection target position reception intensity exceeds the threshold is considered to be closer to the position that is a fixed distance away from the transmission antenna position.

  Based on the above, embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram illustrating a configuration of a database according to an embodiment. As shown in the figure, this database includes a uniform distance calculation unit 11, a radio wave propagation condition setting unit 12, an inspection target position received intensity calculation unit 13, a terrain data storage holding unit 14, a threshold value comparison unit 15, and primary user protection. Area boundary memory holding unit 21, white space available geographic boundary point calculating unit 22, secondary user equipment output radio wave setting unit 23, secondary user equipment interference intensity threshold setting unit 24, radio wave propagation condition setting unit 25, operable area A boundary memory holding unit 26 and a secondary user inquiry reception / answer sending unit 27 are included therein.

  FIG. 1 shows a functional block diagram. In the following, the operation of each of the components in this figure will be described with reference to FIGS. Of the blocks shown in FIG. 1, the configuration from reference numeral 11 (uniform distance calculation unit) to reference numeral 15 (counter value comparison unit) is a functional block for specifying the primary user protection area boundary. First, this point will be described.

  The uniform distance calculation unit 11 calculates a separation distance from the transmission antenna position where the reception intensity from the primary user becomes a predetermined threshold as a uniform distance that does not depend on the direction. At this time, calculation is performed based on radio wave propagation conditions excluding topographic data from the position of the transmitting antenna. More specifically, referring to FIG. 2, calculating the distance d between the primary user receiver 52 and the reception intensity from the primary user transmission antenna 51 at which the reception intensity becomes a predetermined threshold. It is. This calculation uses radio wave propagation conditions excluding topographic data (that is, assuming a flat surface), so the calculated distance d is a uniform distance that does not depend on the direction. The radio wave propagation conditions used here are received from the radio wave propagation condition setting unit 12 which has been set and held in advance.

As shown in FIG. 2, as an equation for calculating the uniform distance d, for example,
Reception strength D = 10 log Pt + 20 log fc + 107.218−Lp (fc, Hb, Hm, d) + Grx
Here, Pt: primary user transmission power [W]
fc: Frequency (channel) [MHz]
Lp: Path attenuation (function of fc, Hb, Hm, d) [dB]
Hb: height of primary user transmitting antenna [m]
Hm: Primary user receiver antenna height [m]
d: Distance between transmission and reception [km]
Grx: primary user receiver antenna gain [dBi]
Can be used.

  That is, if this equation is used, d can be obtained by solving an equation in which these parameter values (that is, radio wave propagation conditions and threshold values) are substituted, except for d. Here, a known method (for example, Hatta model) can be used to calculate the path attenuation Lp. The above formula is an example, and can be changed as appropriate depending on the required accuracy.

  The uniform distance d calculated by the uniform distance calculation unit 11 is passed to the inspection target position reception intensity calculation unit 13. The calculation unit 13 performs the following calculation at the inspection target position in each of the radiation paths centered on the position of the primary user transmission antenna 51. That is, based on the radio wave propagation condition including the terrain data from the position of the transmission antenna 51, the reception intensity from the primary user is calculated as the inspection target position reception intensity. Referring to FIG. 3, at this time, a position gradually approaching the position of the transmitting antenna 51 is applied with the position apart from the uniform distance d as an initial value (P0 → P1 → P2 →...). The terrain data is received from the terrain data storage / holding unit 14 which stores and holds the terrain data in advance.

As shown in FIG. 3, as an equation for calculating the inspection target position reception intensity, for example,
Reception strength D = 10 log Pt + 20 log fc + 107.218−Lp (fc, Hb, Hm, d) −Ld + Grx
Here, Pt: primary user transmission power [W]
fc: Frequency (channel) [MHz]
Lp: Path attenuation (function of fc, Hb, Hm, d) [dB]
Hb: height of primary user transmitting antenna [m]
Hm: Primary user receiver antenna height [m]
d: Distance between transmission and reception [km]
Ld: Diffraction caused by diffraction [dB] (← Estimated using topographic data)
Grx: primary user receiver antenna gain [dBi]
Can be used.

  The topographic data is specifically used to estimate the diffraction-induced attenuation Ld in the above formula. The calculation of the diffraction-induced attenuation Ld can be performed by a known method (for example, the method of Deygout, Epstein-Peterson, Giovaneli, Millington) by applying topographic data. The above formula is an example, and can be changed as appropriate depending on the required accuracy.

  Each time the reception intensity at one inspection position is calculated by the calculation unit 13, the calculated value is passed to the threshold value comparison unit 15. The comparison unit 15 determines whether or not the inspection target position reception intensity passed from the calculation unit 13 exceeds (exceeds) a predetermined threshold value. If not, the process returns to the calculation unit 13 (at that time, the position approaching the transmission antenna 51 is applied as described above). When the threshold value is exceeded, the position from the transmission antenna 51 applied immediately before the position from the transmission antenna 51 that has calculated the inspection target position reception intensity is held as a position specific to the radiation path. The above operations of the calculation unit 13 and the comparison unit 15 are performed in all directions by changing the angle of the radiation path (angle α in FIG. 3). The change in angle can be, for example, every degree, depending on the accuracy required to identify the primary user protection area boundary.

  Thus, a unique position in each radiation path is obtained. A geographic figure obtained by connecting this unique position for all pairs of adjacent radiation paths (hereinafter referred to as a first geographic figure) is as shown in, for example, FIG. This is a schematic of the changes made coarser than the actual ones (the same applies to the following geographical figures). This first geographical figure represents the protected area boundary of the primary user. This is because if it is inside, it can be said that the reception intensity from the primary user exceeds a predetermined threshold value with the accuracy of the distance between the inspection target positions in the radial direction.

  The primary user protection area boundary thus determined is stored and held in the primary user protection area boundary storage holding unit 21. Specifically, the information to be stored can be information on the longitude and latitude of each vertex of the first geographic figure. However, it may be stored and held as a set of sufficiently fine meshed regions.

  By obtaining the protected area boundary of the primary user as described above, terrain data is also utilized, so that the accuracy of calculation is improved. In addition, by applying a position that is obtained without taking terrain data into account and gradually approaching the transmission antenna position using a point at a uniform distance from the transmission antenna position, the received intensity of the inspection target position exceeds a predetermined threshold value. Therefore, it is possible to suppress the calculation amount (processing load) as a whole. This is because the position at which the inspection target position reception intensity exceeds the threshold is considered to be closer to the position that is a fixed distance away from the transmission antenna position. The above processing can be performed in advance.

  Next, an operation that is performed after the above information is stored and held in the primary user protection area boundary storage holding unit 21 will be described. Referring to FIG. 5, in the white space available geographic boundary point calculation unit 22, the primary user receiver 52 located at a position (that is, on the primary user protection area boundary) intersecting with the first geographic figure in each of the radiation paths. The interference intensity U from the received secondary user equipment 61 is checked. Specifically, the secondary user equipment 61 whose interference intensity due to the maximum output radio wave emitted from the secondary user equipment 61 that is separated from the primary user receiver 52 by a distance d on the extension line of the radiation path becomes a predetermined threshold value. Is calculated as a white space available geographic boundary point. At this time, calculation is performed by applying radio wave propagation conditions from the secondary user device 61 to the primary user receiver 52.

As shown in FIG. 5, for the calculation of the disturbance strength U, for example,
Interference intensity U (city area) = 10 log Pt + 10 log Gt + 10 log Gr
+20 log +20 log hr −40 log d−A−B
Interference intensity U (suburb) = 10 log Pt + 10 log Gt + 10 log Gr
+ 20logt + 20loghr-43.36logd-AB
Here, Pt: secondary user equipment maximum transmission power [mW]
Gt: Secondary user equipment transmission gain (linear value)
Gr: primary user receiver reception gain (linear value)
ht: secondary user equipment antenna height [m]
hr: Primary user receiver antenna height [m]
d: distance [m] between secondary user equipment and primary user receiver
A: Urban suburbs dependent attenuation [dB]
B: Building-dependent attenuation [dB]
The following formula can be used.

  That is, if this equation is used, d can be obtained by solving an equation in which these parameter values (that is, radio wave propagation conditions and threshold values) are substituted, except for d. Here, in order to anticipate the case where the secondary user device is outside the building, B = 0 is applied. The above formula is an example, and can be changed as appropriate depending on the required accuracy. The calculation of the white space usable geographical boundary point as described above is performed in all directions by changing the angle of the radiation path.

  Secondary user equipment output radio waves (that is, secondary user equipment maximum transmission power) necessary for calculation in the calculation unit 22 are stored and held in advance as interference intensity threshold values and radio wave propagation conditions by the secondary user equipment. Secondary user equipment output radio wave setting unit 23, secondary user equipment interference intensity threshold setting unit 24, and radio wave propagation condition setting unit 25 respectively.

  Thus, the white space usable geographical boundary point is obtained in each radiation path. A geographic figure obtained by connecting the positions of the boundary points for all pairs of adjacent radiation paths (hereinafter referred to as a second geographic figure) is, for example, as shown in FIG. This second geographic figure directly represents the operable area boundary for the secondary user equipment. This is because if it is outside this, it does not reliably cause significant interference to the primary user receiver that is inside the primary user's protected area boundary. Information on the geographical boundary points where the white space can be used in each radiation path is transferred from the calculation unit 22 to the operable region boundary storage holding unit 26 and stored therein. The above processing can be performed in advance.

  Specifically, as the information storage in the operable area boundary storage holding unit 26, for example, as shown in FIG. 7, the operable area boundary can be held as a set of meshed areas. The operable region boundary is the outermost edge of a region in which meshes in which at least a part of the mesh overlaps the inside of the second geographic figure are gathered. The reason for “at least partly” is that the operable region boundary is set on the safe side with respect to the interference to the primary user receiver. If meshed in this way, processing when a secondary user device inquires about white space is further reduced. This is because it is only necessary to determine which meshing region the current position of the secondary user device belongs to.

  In the state where the information is stored and held in the operable area boundary storage holding unit 26 as described above, when an inquiry about the white space is received from the secondary user device, it can be received and answered. Specifically, when an inquiry is made from a secondary user device that is about to start operation, the secondary user inquiry reception / answer sending unit 27 refers to the memory holding unit 26 and the current position of the secondary user device If it is outside the operable area boundary, an answer indicating that the operation is possible is sent to the secondary user equipment.

  Whether or not the secondary user device can be operated is restricted at least at the same frequency as the frequency (channel) of the primary user. You may make it reply as a regulation object to (± 1 channel). This is because a spurious toward the side wave side of the radio wave generated by the secondary user device is expected. This also applies to the modified examples and forms described below.

  As described above, in this database, both the protected area boundary of the primary user and the operable area boundary related to the secondary user equipment are adjacent to a predetermined point on the radiation path centering on the transmitting antenna position of the primary user. It is stored and held on the basis of geographic figures (first and second geographic figures) obtained by connecting all pairs of matching radiation paths. Here, when calculating the first geographic figure, the terrain data can also be used and the accuracy can be improved. The first geographic figure is used for calculating the operable region boundary.

  Based on the fact that the operable region boundary and the protected region boundary can be calculated in advance by using the radiation path in this way, the processing (calculation) burden as a database can be reduced, and the accuracy can be improved. By calculating in advance, a quick answer can be sent to the secondary user device.

  Next, a modified example of the database described above will be described. The calculation unit 22 in the modified example also pays attention when the secondary user equipment emits a reduced radio wave having a lower power than the maximum output radio wave when calculating the white space usable geographical boundary point. In other words, the position of the secondary user equipment whose threshold is the disturbance intensity received by the primary user receiver at that time is calculated as the second type white space available geographical boundary point.

  The storage holding unit 26 is based on a geographical figure (hereinafter referred to as a third geographical figure) represented by connecting the second type white space available geographical boundary points for all pairs of adjacent radial paths. Stores and holds an operable area boundary (hereinafter referred to as a second type operable area boundary) related to the secondary user equipment. In this way, the operational area boundary that can be operated with the maximum output radio wave and the second type operational area boundary that can be operated with the reduced radio wave are calculated. Depending on the location, an answer may be given that it can be operated with reduced radio waves.

  That is, when an inquiry about white space is made from a secondary user device that is about to start operation, the secondary user inquiry reception / answer sending unit 27 refers to the storage holding unit 26 to determine the current location of the secondary user device. If it is outside the operational area boundary, it can respond with the maximum output radio wave. If it is inside the operational area boundary and outside the second type operational area boundary, it can be operated with the reduced radio wave. An answer to the effect can be sent to the secondary user device if it is inside the boundary of the second type operable area.

  In this way, the situation where the secondary user equipment effectively uses the frequency band is enhanced. Moreover, the calculation of the second type operable area boundary can be performed in the same procedure as the calculation of the operable area boundary as described above, and the processing complexity does not increase particularly. It is also possible to classify the reduced radio waves more finely and calculate the second type operable area boundary for each class. This makes it possible to provide more detailed information. When the above-mentioned third geographic figure is obtained with two classes of reduced radio waves, for example, the result is schematically shown in FIG. Similarly to the second geographic figure, the third geographic figure can also hold information as a set of meshed areas in the storage holding unit 26 (see description in FIG. 7).

  FIG. 9 is an explanatory diagram illustrating the contents of specific information related to the operable area boundary held by the operable area boundary storage holding unit 26 shown in FIG. Information obtained by the procedure described above can be stored in a database with the information structure shown in FIG. That is, a pair of the longitude range and the latitude range is given corresponding to the mesh, and a channel and its allowable transmission power are stored and held corresponding to the pair.

  Next, another embodiment will be described with reference to FIG. FIG. 10 is a functional block diagram showing the configuration of a database according to another embodiment. As shown in the figure, this database includes an operable area boundary storage holding unit 26, a secondary user inquiry reception / answer transmission unit 27A, a primary user receiver reception intensity calculation unit 31, a radio wave propagation condition setting unit 32, 1 Secondary user receiver interference intensity calculation unit 33, radio wave propagation condition setting unit 34, allowable transmission output calculation unit 35, threshold setting unit 36, weak protection white space information storage holding unit 37, primary user receiver information acquisition unit 41, A primary user receiver position memory holding unit 42 is provided therein.

  FIG. 10 shows a functional block diagram. In the following, when the operation of each of the components in this figure is described, FIGS. 11 to 13 will be referred to as appropriate. First, the operable area boundary storage holding unit 26 in FIG. 10 is the same as that shown in FIG. The process for calculating the information to be held in the storage holding unit 26 is as described with reference to FIGS. 1 to 9 (the configuration for that is not shown here).

  This form is another configuration example for providing detailed information. According to this form, as described below, the primary user receiver is significant even within the protection area boundary of the primary user. White space can be discovered under the condition that it is not subject to significant interference. Therefore, the situation where the frequency band is effectively used further increases. Then, the allowable transmission power of the secondary user equipment is determined under the condition that no significant interference is caused to the primary user receiver within a predetermined distance from the secondary user equipment.

  The primary user receiver reception intensity calculation unit 31 refers to the storage holding unit 26, and in each of the radiation paths, the primary user at the inspection target position that is closer to the transmission antenna position than the white space available geographical boundary point The reception intensity D from the primary user in the receiver 53 (see FIG. 11) is calculated. At this time, radio wave propagation conditions from the position of the transmission antenna to the primary user receiver 53 are applied. The radio wave propagation condition used here is received from the radio wave propagation condition setting unit 32 that is set and held in advance. The formula for this calculation is, for example, the formula shown in FIG. The calculated reception strength D is sent to the allowable transmission output calculation unit 35.

  Further, the primary user receiver disturbance intensity calculating unit 33 is based on radio waves emitted by the secondary user device 62 at the inspection target position received by the primary user receiver 53 located at a predetermined distance from the inspection target position on the radiation path. The interference strength U is estimated as a function of its transmission power. At this time, radio wave propagation conditions from the secondary user device 62 to the primary user receiver 53 are applied. The radio wave propagation condition used here is received from the radio wave propagation condition setting unit 34 that is set and held in advance. The formula for this calculation is, for example, the formula shown in FIG. The estimated interference strength U as a function of transmission power is sent to the allowable transmission output calculation unit 35.

  In the estimation of the interference strength U, in the illustration in FIG. 11, the positions of the primary user receiver 53 and the secondary user device 62 are opposite to those described above. This is because the predetermined distance is assumed to be a very short distance (for example, about 10 m). When viewed from the primary user transmitting antenna 51, the primary user receiver 53 and the secondary user equipment 62 that are separated by such a distance are effectively at the same position.

  The allowable transmission power calculation unit 35 uses the reception strength D sent from the calculation unit 33 and the interference strength U sent from the calculation unit 35 as a function of the transmission power, The transmission power of the secondary user equipment 62 at which the difference between the two becomes a predetermined threshold is calculated as the allowable transmission power. The allowable transmission power obtained in this way is not necessarily a positive numerical value, but it may be obtained as a positive numerical value as the reception strength D from the primary user increases.

  Therefore, when it is obtained as a positive numerical value, it is determined that there is a white space that can be operated by the secondary user device within the range of the allowable transmission power at the inspection target position (see FIG. 12). Information regarding the white space thus discovered is stored and held in the white space information storage holding unit 37 during weak protection as a set of the position and the allowable transmission power.

  The discovery of the new operable area as described above can be performed by sequentially setting the positions on the radiation path closer to the transmission antenna position than the white space usable geographical boundary point as the inspection target positions in each of the radiation paths. The final discovery result is schematically shown in FIG. 13, for example. Such a new operable area is found on the condition that the reception intensity from the primary user is very strong, and that it is not significantly disturbed as a primary user receiver even by the operation of the nearby secondary user equipment. Therefore, as shown in FIG. 13, the closer to the primary user transmission antenna 51, the higher the possibility of discovery.

  In addition, although the distance between the primary user receiver 53 and the secondary user device 62 in FIG. 11 is assumed to be about 10 m, this means that even if the secondary user device 62 is operated at the illustrated position, If the primary user receiver 53 is separated from the secondary user equipment 62 by a distance of 10 m or more, it means that the primary user receiver 53 is not significantly disturbed.

  In this database, when an inquiry about white space is made from a secondary user device that is about to start operation, the secondary user inquiry reception / answer sending unit 27A refers to the memory holding unit 26 already described, and also provides weak protection. The response is sent to the secondary user with reference to the hour white space information storage holding unit 37 as well. That is, if the current position of the secondary user equipment is effectively the same position as the inspection target position on the radiation path that is found as having a white space, a reply that it can be operated within the allowable transmission power range is given. It can be sent to the next user equipment.

  Here, “effectively the same position” may be a case where the position is located in the same mesh as the mesh including the position found as having a white space. Alternatively, if the mesh settings are finer, it may be a case where the mesh is located within a set of meshes including a position found as having white space and a mesh located somewhat around (for example, adjacent). .

  Next, operations of the primary user receiver information acquisition unit 41 and the primary user receiver position storage holding unit 42 shown in FIG. 10 will be described below. These blocks are provided to achieve the functions as modified examples of the operations described above. In the following, the operation of these blocks will be described with reference to FIGS. 14 and 15 as appropriate.

  In this modification, more specifically, any of the primary user receivers (not limited to one and any number) that are actually used (viewed) at a known distance from the secondary user equipment. The allowable transmission power of the secondary user equipment is determined under the condition that no significant interference occurs. Therefore, in order to acquire information on whether or not the primary user receiver is actually viewed, and to acquire the position information thereof, the primary user receiver information acquisition unit 41 is provided. If the primary user receiver is to be used by moving, the position information is obtained, and the distance from the secondary user device is obtained and used for estimating the interference intensity. .

  Information about whether or not the primary user receiver is actually viewed is collected using, for example, the Internet, and the collected information is held in the primary user receiver information acquisition unit 41, as necessary. It can be referred to by the secondary user inquiry reception / answer sending unit 27A. Similarly, the location information of the primary user receiver is collected using the Internet or the like, and is stored and held in the primary user receiver location storage holding unit 42.

  In this modification, the operation of the primary user receiver reception strength calculation unit 31 is the same as that already described (see FIG. 14 and the primary user receiver 54 in the figure).

  The primary user receiver disturbance intensity calculation unit 33 receives the secondary user equipment at the inspection target position received by the primary user receiver 55 (see FIG. 15) at a known distance from the inspection target position on the radiation path. The interference intensity U due to the radio wave emitted by 63 (see FIG. 6) is estimated as a function of the transmission power. Here, the “known distance away” is because the calculating unit 33 obtains information on the actual position of the primary user receiver 55 from the storage holding unit 42. Such estimation is performed for each primary user receiver 55 that is likely to be disturbed in consideration of the distance from the secondary user device 63 described above. The estimated interference strength U as a function of transmission power is sent to the allowable transmission output calculation unit 35.

  The allowable transmission power calculation unit 35 uses the reception strength D sent from the calculation unit 33 and the interference strength U sent from the calculation unit 35 as a function of the transmission power, The transmission power generated by the secondary user device 63 whose difference is a predetermined threshold is calculated as the allowable transmission power. This calculation is performed for each primary user receiver 55 in which a plurality of units are assumed. Each of the permissible transmission powers obtained in this way is not necessarily a positive numerical value, but may be obtained as a positive numerical value as the reception strength D from the primary user increases.

  Therefore, when it is obtained as a positive numerical value, it is determined that there is a white space that can be operated by the secondary user equipment within the range of the allowable transmission power at the inspection target position with the primary user receiver as a caution target. . The information related to the white space thus discovered is stored and held in the weak protection white space information storage holding unit 37 as a set of the position, the allowable transmission power, and the identifier of the primary user receiver that is the object of attention. The

  The discovery of the new operable area as described above can be performed by sequentially setting the positions closer to the transmitting antenna position than the white space usable geographical boundary points as the inspection target positions in each of the radiation paths.

  In the case of this modification, the secondary user inquiry reception / answer sending unit 27A refers to the memory holding unit 26 already described when an inquiry about white space is made from the secondary user device that is about to start operation. First, referring to the primary user receiver information acquisition unit 41, the primary user receivers that are actually used (viewed) around the secondary user device are determined, and then the result of the determination is obtained. In addition, an information search is performed with respect to the white space information storage holding unit 37 during weak protection to create an answer.

  Specifically, information that the current position of the secondary user device is effectively at the same position as the inspection target position on the radiation path and there is no primary user receiver that is actually used in the surrounding area is information acquisition unit 41. If it is obtained from the above, a reply indicating that the operation is possible within a predetermined allowable transmission power range is sent to the secondary user device.

  In addition, the current position of the secondary user equipment is effectively at the same position as the inspection target position on the radiation path, and one or more of the primary user receivers around it are used, and others are used. If the information acquisition unit 41 obtains information indicating that no transmission power is available, a reply indicating that operation is possible within the range of the weakest transmission power among the allowable transmission powers for the one or more primary user receivers is given. Send to secondary user equipment. “Effectively the same position” is as described above.

  If there are two primary user receivers around the inquired secondary user device, (1) the channel to be regulated by the secondary user device is not viewed by both. Responds that it can be operated within a predetermined allowable transmission power range. (2) If only one is being viewed, the operation is within the allowable transmission power range for the primary user receiver being viewed. Answer that it is possible, (3) If both are also viewed, reply that it is possible to operate within the range of allowable transmission power of the smaller of the allowable transmission power for those Become.

  Even in the case of this modification, the information that needs to be confirmed whether or not the state has changed in response to the inquiry depends on whether or not the primary user receivers around the secondary user equipment are actually used. Yes, other processes can be performed in advance. Therefore, there are very few factors that hinder quick responses to inquiries from secondary user devices.

  DESCRIPTION OF SYMBOLS 11 ... Uniform distance calculation part, 12 ... Radio wave propagation condition setting part, 13 ... Inspection object position received intensity calculation part, 14 ... Topography data storage holding part, 15 ... Counter threshold comparison part, 21 ... Primary user protection area boundary storage holding , 22 ... White space available geographical boundary point calculation part, 23 ... Secondary user equipment output radio wave setting part, 24 ... Secondary user equipment interference intensity threshold setting part, 25 ... Radio wave propagation condition setting part, 26 ... Operable Area boundary memory holding unit, 27, 27A ... secondary user inquiry reception / answer sending unit, 31 ... primary user receiver reception intensity calculation unit, 32 ... radio wave propagation condition setting unit, 33 ... primary user receiver interference intensity calculation 34 ... Radio wave propagation condition setting unit 35 ... Allowable transmission power calculation unit 36 ... Threshold setting unit 37 ... Weak protection white space information storage holding unit 41 ... Primary user receiver information acquisition unit 42 ... Next the user receiver position storage holding unit, 51 ... primary user transmitting antenna, 52, 53, 54, 55 ... primary user receiver, 61, 62, 63 ... secondary user equipment.

Claims (5)

A first geographical figure representing a point at each predetermined distance away from the center of each of the radiation paths centered on the transmission antenna position of the primary user, with respect to all pairs of adjacent radiation paths. Means for storing and retaining the protected area boundary of the primary user based on the geographical figure of
As a first means for calculating the first geographic figure, a distance from the transmission antenna position at which a reception intensity from the primary user becomes a predetermined threshold is calculated as a topography from the transmission antenna position. Based on radio wave propagation conditions excluding data, a means to calculate as a uniform distance independent of direction,
As a second means for calculating the first geographical figure, a position gradually approaching the transmission antenna position is applied to each of the radiation paths, with a position at a uniform distance from the transmission antenna position as an initial value. A means for calculating a reception intensity from the primary user as an inspection target position reception intensity based on a radio wave propagation condition including terrain data from the transmission antenna position;
Means for determining whether the inspection target position reception intensity exceeds a predetermined threshold as a third means for calculating the first geographic figure;
As a fourth means for calculating the first geographic figure, the position of the position from the transmission antenna that has calculated the inspection target position reception intensity when the inspection target position reception intensity exceeds the threshold value for the first time. Means for setting a position from the transmitting antenna applied immediately before as a position away from the predetermined distance in the first geographic figure;
Maximum output from a secondary user equipment at a distance on the extension of the radiation path from the primary user receiver received by a primary user receiver at a position intersecting the first geographic figure in each of the radiation paths The position of the secondary user device where the interference intensity due to the radio wave becomes a predetermined threshold is set as a white space usable geographical boundary point based on the radio wave propagation condition from the secondary user device to the primary user receiver. Means to calculate,
Based on the second geographic figure, which is the geographic figure represented by connecting the white space available geographic boundary points for all pairs of the adjacent radial paths, the operational area boundary for the secondary user equipment is stored and held. Means,
When an inquiry about white space is made from a secondary user device that is about to start operation, a reply that the current position of the secondary user device is outside the operable area boundary A database comprising means for sending a reply to the secondary user device that the operation is not possible if the current position of the next user device is inside the operable area boundary. In calculating the white space available geographic boundary point, in addition to calculating the white space available geographic boundary point, when the secondary user equipment emits a reduced radio wave having a lower power than the maximum output radio wave, Calculating the location of the secondary user equipment at which the disturbance intensity received by the primary user receiver is the threshold value as the second type white space available geographical boundary point;
Based on a third geographic figure, which is a geographic figure represented by connecting the second type white space available geographic boundary points for all pairs of the adjacent radial paths, Means for storing and holding operational area boundaries;
When an inquiry about white space is made from the secondary user equipment that is about to start operation, if the current position of the secondary user equipment is outside the operable area boundary, it can be operated with the maximum output radio wave. If the current location of the secondary user device is inside the operable area boundary and outside the second type operable area boundary, an answer that the reduced radio wave can be used is And a means for sending, to the secondary user equipment, a reply indicating that the secondary user equipment cannot be operated if the current position of the secondary user equipment is inside the second type operable area boundary. Item 1. The database according to item 1. In each of the radiation paths, the reception intensity from the primary user at the primary user receiver at the inspection target position that is a position on the radiation path that is closer to the transmission antenna position than the geographical boundary point where the white space is available. Means for calculating based on radio wave propagation conditions from the transmitting antenna position to the primary user receiver;
The interference intensity caused by the radio wave emitted by the secondary user equipment at the inspection target position on the radiation path received by the primary user receiver located at a predetermined distance from the inspection target position on the radiation path is represented by the secondary user. Means for estimating based on radio wave propagation conditions from a device to the primary user receiver;
Means for calculating, as an allowable transmission power, a transmission power generated by the secondary user equipment, wherein a difference between the reception strength and the interference strength becomes a predetermined threshold;
When an inquiry about white space is received from a secondary user device that is about to start operation, if the current position of the secondary user device is effectively at the same position as the inspection target position on the radiation path, the allowable transmission is performed. The database according to claim 1, further comprising means for sending an answer indicating that the operation is possible within a range of power to the secondary user device. In each of the radiation paths, from the primary user at a first primary user receiver at a position to be examined that is a position on the radiation path that is closer to the transmission antenna position than the white space available geographic boundary point. Means for calculating received intensity based on radio wave propagation conditions from the transmitting antenna position to the first primary user receiver;
The interference intensity due to the radio wave emitted by the secondary user equipment at the inspection target position on the radiation path received by the second primary user receiver located at a known distance from the inspection target position on the radiation path. Means for estimating a first jamming strength based on radio wave propagation conditions from the secondary user equipment to the second primary user receiver;
Means for calculating, as a first allowable transmission power, a transmission power generated by the secondary user equipment, wherein a difference between the signal strength and the first interference strength is a predetermined threshold;
Interference by radio waves emitted by the secondary user equipment at the inspection target position on the radiation path received by a third primary user receiver located at another known distance from the inspection target position on the radiation path Means for estimating a second jamming strength that is a strength based on radio wave propagation conditions from the secondary user equipment to the third primary user receiver;
Means for calculating, as a second allowable transmission power, a transmission power generated by the secondary user equipment, wherein a difference between the signal strength and the second interference strength is the predetermined threshold;
Information indicating whether or not the second primary user receiver and the third primary user receiver are used is indicated by the second primary user receiver and the third primary user receiver. Means to obtain each from
When an inquiry about white space is made from a secondary user device that is about to start operation, the current position of the secondary user device is effectively at the same position as the inspection target position on the radiation path, and the second user device When information indicating that neither the primary user receiver nor the third primary user receiver is used is acquired, an answer indicating that operation is possible within a predetermined allowable transmission power range is performed. The current position of the secondary user equipment is effectively the same position as the inspection target position on the radiation path, and the second primary user receiver is used, and the third primary user receiver is If information indicating that the secondary user equipment is not used is acquired, a reply indicating that it can be operated within the range of the first allowable transmission power is given, and the current position of the secondary user equipment is the inspection target on the radiation path. Position and effectiveness And the second primary user receiver is not used and the information indicating that the third primary user receiver is used is acquired. An answer to the effect that operation is possible within the range of allowable transmission power is made as follows. The second primary user receiver is configured such that the current position of the secondary user equipment is effectively the same as the inspection target position on the radiation path. And when the information indicating that both of the third primary user receivers are being used is acquired, the smaller allowable transmission power range of the first and second allowable transmission powers The database according to claim 1, further comprising means for sending an answer indicating that the operation is possible to the secondary user device.   The database according to claim 1, wherein an area inside the operable area boundary is stored and held as a set of meshed areas.

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