Site survey device, site survey program, and site survey method

Abstract

To provide a site survey device, a site survey program, and a site survey method that can reduce measurement time while ensuring the reliability of measurement results.SOLUTION: In a wireless communication system 1, a site survey device 10 performs a site survey of radio waves transmitted from a transmitter 20. The site survey device 10 includes an acquisition unit 12 that acquires results of radio wave measurements taken by a receiver 30 while the receiver is moved to a plurality of positions, and a control unit 14 that generates a map that displays measurement position information about the plurality of positions in association with the results of radio wave measurements by the receiver 30.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a site survey device, a site survey program, and a site survey method.

Background Art

[0002] Conventionally, a wireless information collection method executed by a user terminal device that measures wireless information and a server device that accumulates wireless information and conducts a site survey is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a site survey of field wireless, the radio wave intensity and error rate at each of a plurality of measurement points are measured. In order to ensure the reliability of the measurement results at each measurement point, more than several hundred measurement samples are required.

[0005] In normal operation of field wireless, it takes several seconds to obtain one measurement sample. Therefore, in order to measure more than several hundred samples required to ensure the reliability of the measurement results, it takes several tens of minutes to several hours per measurement point. In this case, the larger the number of measurement points, the longer the time required to complete the site survey. It is required to shorten the measurement time while ensuring the reliability of the measurement results.

[0006] The present disclosure has been made in view of the above points, and an object thereof is to provide a site survey device, a site survey program, and a site survey method capable of shortening the measurement time while ensuring the reliability of the measurement results. [Means for solving the problem]

[0007] (1) Some site survey devices according to certain embodiments are site survey devices that perform a site survey of radio waves transmitted from a transmitter, and include an acquisition unit that acquires the results of measuring radio waves while a receiver moves to a plurality of locations, and a control unit that generates a map that displays the measurement results of radio waves by the receiver in association with measurement position information for the plurality of locations.

[0008] By having the receiver move to multiple locations while measuring radio waves, measurement results for a wide area can be obtained in a short time. Obtaining measurement results for a wide area in a short time makes it easier to find locations with good radio wave reception. In addition, because the radio wave measurement results are obtained as a line rather than a point, the distribution of radio wave reception conditions at each location along the path the receiver moves can be visualized.

[0009] (2) In the site survey device described in (1) above, the receiver may acquire a predetermined number or more measurement results while located within a predetermined range. The predetermined range may be set such that the difference between each measurement result measured while located within the predetermined range falls below a judgment threshold set as a condition for the site survey. The predetermined number may be a number set as a condition necessary to ensure the reliability of the measurement results of the radio waves.

[0010] (3) In the site survey device described in (2) above, the speed at which the receiver moves within the predetermined range may be determined such that the value obtained by dividing the time the receiver is located within the predetermined range by the interval at which the transmitter transmits radio waves is equal to or greater than the predetermined number.

[0011] (4) In the site survey device described in (2) or (3) above, the acquisition unit may acquire information that identifies the predetermined range as the measurement location information. The control unit may generate the map so as to associate the results of processing the predetermined number of measurement results with the predetermined range.

[0012] By processing the measurement results of radio waves at multiple measurement locations as the measurement results for a single measurement range, numerous measurement results can be obtained within a single measurement range even when the receiver is moving during measurement. As a result, the reliability of the measurement results within a single measurement range is ensured.

[0013] (5) In the site survey device described in any one of (1) to (3) above, the acquisition unit may acquire the position of the receiver at the start of a period in which the receiver is assumed to be moving at a constant speed as the starting position. The acquisition unit may acquire each measurement result when the receiver measures radio waves during the period in which the receiver is assumed to be moving at a constant speed. The acquisition unit may acquire the position of the receiver at the end of the period in which the receiver is assumed to be moving at a constant speed as the ending position. The control unit may calculate the measurement position between the starting position and the ending position by interpolation as the measurement position information during the period in which the receiver is assumed to be moving at a constant speed.

[0014] By interpolating and calculating the measurement position by assuming that the receiver moves at a constant velocity along a straight path between the start and end positions, the data size of the position information output from the receiver is reduced. Furthermore, the measurement position can be calculated even if the receiver does not have a position information acquisition unit.

[0015] (6) In the site survey device described in any one of (1) to (5) above, the acquisition unit may acquire measurement results of radio waves transmitted from each of the multiple transmission points. The control unit may generate a superimposed map that displays the measurement results of radio waves transmitted from each of the transmission points superimposed on each other.

[0016] (7) In the site survey device described in (6) above, the control unit may display on the superimposed map or on at least one of the maps displaying the measurement results of radio waves transmitted from each transmission point that satisfy the conditions required for radio wave reception status.

[0017] By generating a map that displays the measurement results of radio waves transmitted from a plurality of points, the location where a repeater is to be installed between the plurality of points can be easily determined.

[0018] (8) A site survey program according to some embodiments causes a processor to execute steps of obtaining measurement results of radio waves transmitted from a transmitter while a receiver moves to a plurality of positions, and generating a map that associates and displays the measurement results of the radio waves with measurement position information regarding the plurality of positions.

[0019] (9) A site survey method according to some embodiments includes steps of a site survey device that performs a site survey of radio waves transmitted from a transmitter obtaining measurement results of the radio waves transmitted from the transmitter while the receiver moves to a plurality of positions, and the site survey device generating a map that associates and displays the measurement results of the radio waves with measurement position information regarding the plurality of positions.

Advantages of the Invention

[0020] According to the site survey device, site survey program, and site survey method according to the present disclosure, the measurement time is shortened while ensuring the reliability of the measurement results.

Brief Description of the Drawings

[0021] [Figure 1] It is a block diagram showing the configuration of a system according to a comparative example. [Figure 2] It is a timing chart of radio wave transmission in a system according to a comparative example. [Figure 3] It is a block diagram showing a configuration example of a wireless communication system according to the present disclosure. [Figure 4] It is a timing chart of radio wave transmission in a system according to the present disclosure. [Figure 5] It is a diagram showing an example of a measurement position on the movement path of a receiver. [Figure 6]This is an example of a map that displays the measurement results of radio waves in a plant. [Figure 7] This is a flowchart showing an example of the procedure of the site survey method according to the present disclosure. [Figure 8A] This is an example of a map that displays the measurement results of radio waves transmitted from the first location. [Figure 8B] This is an example of a map that displays the measurement results of radio waves transmitted from the second location. [Figure 9] This is a diagram showing an example of the relationship between the start position and the end position of the constant-speed movement period of the receiver, and the measurement positions interpolated within the constant-speed movement period. [Figure 10] This is a flowchart showing an example of the procedure of the site survey method when the receiver is considered to move at a constant speed. [Embodiment for Carrying Out the Invention]

[0022] (Comparative Example) As shown in FIG. 1, the wireless communication system 90 according to the comparative example includes a site survey device 91, a transmitter 92, and a receiver 93. The transmitter 92 sends out packets by transmitting radio waves. The receiver 93 receives the radio waves transmitted by the transmitter 92 and acquires the radio wave intensity or the reception error rate, etc. as the measurement result of the radio waves. The site survey device 91 acquires the measurement result of the radio waves by the receiver 93 and the information on the measurement position of the receiver 93, and associates the measurement result of the radio waves with the measurement position and displays it as a map.

[0023] The site survey device 91 acquires several hundred samples as the measurement result of the radio waves at one measurement position in order to ensure the reliability of the measurement result of the radio waves. Here, it is assumed that N transmitters 92 are operating in the wireless communication system 90. In this case, in the wireless communication system 90, the N transmitters 92 transmit radio waves in order. One transmitter 92 to be the target of the site survey is also referred to as the target transmitter. The site survey device 91 measures the radio waves transmitted from one transmitter 92 that is the target of the site survey among the N transmitters 92.

[0024] As shown in the timing chart in Figure 2, the N transmitters 92, including the target transmitter and N-1 other transmitters, transmit radio waves such that the interval between each transmitter 92 transmitting radio waves to send out packets is represented by the time interval T'. In Figure 2, the horizontal axis represents time. In Figure 2, the timing of when the transmitters 92 transmit radio waves is represented by vertical bars. Here, the time interval between when the transmitters 92 transmit radio waves is assumed to be longer than the packet interval defined by the wireless communication standard. The packet interval is determined based on the minimum idle time that must be provided between packets.

[0025] When N transmitters 92 transmit radio waves in sequence, the interval between transmitters is T' × N. If the number of transmitters 92 operating in the wireless communication system 90 is large, such as tens or hundreds of units, the interval between transmitters will become very long.

[0026] Furthermore, measuring the radio waves transmitted by the target transmitter and obtaining hundreds of samples requires hundreds of times T' × N of time. This means that a very long time is needed to ensure the reliability of the measurement results for the radio waves transmitted by the target transmitter at a single measurement location. Conversely, a very long time is needed to increase the number of measurement locations. Consequently, when conducting a site survey within a limited time, the number of locations where radio wave reception conditions can be measured becomes limited.

[0027] The results of the site survey are used to determine the placement of receivers or repeaters. A certain level of radio knowledge and experience is required to appropriately place receivers or repeaters based on measurement results from a limited number of locations.

[0028] Therefore, this disclosure describes a site survey method that enables a person with limited wireless knowledge or experience to obtain sufficient measurement results for the proper placement of receivers or repeaters during a site survey within a limited timeframe.

[0029] (Example configuration of wireless communication system 1) As shown in Figure 3, a wireless communication system 1 according to one embodiment of the present disclosure comprises a site survey device 10, a transmitter 20, and a receiver 30. In the wireless communication system 1, the transmitter 20 transmits radio waves. The receiver 30 receives the radio waves transmitted by the transmitter 20 at multiple measurement locations and acquires radio wave strength or error rate as the measurement result of the radio waves. The site survey device 10 acquires the measurement result of the radio waves at each measurement location and the measurement location information of the receiver 30, and displays the relationship between each measurement location and the measurement result of the radio waves as a map.

[0030] <Transmitter 20 and Receiver 30> Transmitter 20 transmits a packet containing an address, a sequence number, and transmission data by transmitting radio waves. The address is a unique number assigned to each transmitter 20 in wireless communication, and includes, for example, a MAC (Media Access Control) address. In this embodiment, the address is assumed to be a 64-bit number based on the EUI-64 (Extended Unique Identifier 64-bit) standard. The sequence number is a number assigned to the packet in the order in which it is transmitted by transmitter 20.

[0031] During a site survey, radio waves are transmitted to measure signal strength or error rate. The error rate represents the percentage of the content of packets received by the receiver 30 that is incorrect compared to the content of packets sent by the transmitter 20. The content of the packets is not fixed and may be predetermined or random.

[0032] The radio wave strength is measured regardless of the packet content. Therefore, when the radio wave strength is measured, the radio waves do not necessarily have to be transmitting packets, as long as the source transmitter 20 can be identified.

[0033] The transmitter 20 can send packets at a packet interval defined by the wireless communication standard. The packet interval is determined based on the minimum idle time required between packets. For example, if the wireless communication standard is ISA100, the packet interval defined by the wireless communication standard is 4 milliseconds. The packet interval defined by the wireless communication standard is not limited to 4 milliseconds and can be any other value. The time interval at which the transmitter 20 sends packets is not limited to the packet interval and may be set to a value longer than the packet interval.

[0034] The receiver 30 receives radio waves transmitted from the transmitter 20 to send packets and measures the signal strength (RSSI; Received Signal Strength Indicator) or error rate (PER; Packet Error Rate). Based on the address contained in the packet, the receiver 30 can identify the transmitter 20 that sent the packet. Here, the transmitter 20 that is the target of the site survey in the wireless communication system 1 is also called the target transmitter. Based on the address contained in the received packet, the receiver 30 identifies the packet sent from the target transmitter and measures the signal strength and error rate of the packet sent from the target transmitter.

[0035] The receiver 30 may include a location information acquisition unit. The location information acquisition unit is configured to acquire the location information of the receiver 30 itself. The receiver 30 may transmit its own location information at the time of radio wave measurement to the site survey device 10. The location information acquisition unit may be configured as a receiver compatible with a satellite positioning system such as GPS (Global Positioning System). The location information acquisition unit is not limited to the above example and may be configured to acquire the location information of the receiver 30 itself using various other positioning technologies, such as positioning based on radio waves transmitted from a wireless LAN access point.

[0036] The transmitter 20 and receiver 30 may be implemented by a transmitter capable of both wireless transmission and reception.

[0037] <Site survey device 10> The site survey device 10 comprises an acquisition unit 12, a control unit 14, and a storage unit 16.

[0038] The acquisition unit 12 may include a communication interface for communicating with external devices such as a transmitter 20 or receiver 30, for example, by wired or wireless connection. The communication interface may be configured to communicate based on a communication standard such as a LAN (Local Area Network). The communication standard is not limited to LAN and may be various other standards.

[0039] The control unit 14 may be configured to include, for example, a processor such as a CPU (Central Processing Unit) or a dedicated circuit such as an FPGA (Field Programmable Gate Array). The control unit 14 may be configured to execute a program that realizes the functions of the site survey device 10.

[0040] The storage unit 16 may store various information used for the operation of the site survey device 10, or programs that realize the functions of the site survey device 10. The storage unit 16 may function as the work memory of the control unit 14. The storage unit 16 may be composed of, for example, a semiconductor memory. The storage unit 16 may be configured as an integral part of the control unit 14 or as a separate unit.

[0041] The site survey device 10 may include an input device that accepts input from the user. The input device may include, for example, a keyboard or physical keys, or a pointing device such as a touch panel or touch sensor or mouse.

[0042] The site survey device 10 may include a display device. The display device may include various displays, such as liquid crystal displays. The site survey device 10 may include an interface for outputting the information to be displayed to an external display device. The site survey device 10 may include an audio output device, such as a speaker. The site survey device 10 may include an interface for outputting audio information to an external speaker or the like.

[0043] The site survey device 10 may be configured as an integral part of the receiver 30. In other words, the site survey device 10 may perform the functions of the receiver 30. When the site survey device 10 is configured as an integral part of the receiver 30, the site survey device 10 moves and measures radio waves at multiple measurement locations, and acquires the measurement results of radio waves at each measurement location.

[0044] (Example of operation of wireless communication system 1) In the wireless communication system 1 according to this embodiment, the site survey device 10 performs a site survey of radio waves transmitted from the transmitter 20. An example of the operation of performing a site survey in the wireless communication system 1 will be described below.

[0045] <Measurement of radio waves> The target transmitter transmits radio waves at time intervals represented by T, as shown as a timing chart in Figure 4, in order to send packets, regardless of the number of transmitters 20 operating in the wireless communication system 1. In Figure 4, the horizontal axis represents time. In Figure 4, the timing at which the target transmitter transmits radio waves is represented by vertical bars. The time interval (T) at which the target transmitter transmits radio waves may be set to the packet interval defined in the wireless standard, or it may be set to an interval longer than the packet interval. In this embodiment, the interval (T) at which the target transmitter sends packets is set to 4 milliseconds, which is the packet interval defined in the wireless standard.

[0046] In the wireless communication system 1, the target transmitter may transmit radio waves regardless of the timing at which other transmitters transmit radio waves. The receiver 30 determines whether the source of the received packet is the target transmitter or another transmitter based on the address contained in the received packet. The receiver 30 measures the radio wave strength and error rate of the packet transmitted from the target transmitter and outputs the measurement results to the site survey device 10.

[0047] On the other hand, in the wireless communication system 90 of the comparative example described above, multiple transmitters 92 transmit radio waves sequentially, as shown as a timing chart in Figure 2. Therefore, in the wireless communication system 1 according to this embodiment, the target transmitter can transmit radio waves at shorter intervals than the transmitter 92 of the comparative example. Because the radio waves are transmitted at shorter intervals, the receiver 30 can measure more radio waves than the receiver 93 of the comparative example. As a result, the site survey device 10 can acquire more measurement results than the site survey device 91 of the comparative example.

[0048] As illustrated in Figure 5, the receiver 30 may measure radio waves while sequentially moving to each of the measurement positions 61 to 65. The receiver 30 outputs the radio wave strength or error rate, etc., at each of the measurement positions 61 to 65 to the site survey device 10 as the radio wave measurement result. The acquisition unit 12 of the site survey device 10 acquires the radio wave measurement results from the receiver 30. In other words, the acquisition unit 12 acquires the results of the receiver 30 measuring radio waves while moving to multiple positions.

[0049] The receiver 30 outputs location information for each of the measurement positions 61 to 65 to the site survey device 10. In other words, the receiver 30 outputs measurement location information for multiple locations where radio waves were measured to the site survey device 10. The acquisition unit 12 of the site survey device 10 acquires the measurement location information from the receiver 30. The measurement location information includes the location information of the receiver 30 itself when it measured radio waves at each of the multiple locations. The acquisition unit 12 acquires the results of the receiver 30 measuring radio waves while moving to the multiple locations, along with the location information at each time the radio waves were measured.

[0050] <Map generation> The control unit 14 of the site survey device 10 generates a map that displays the measurement results of radio waves in association with the measurement location information. For example, as shown in Figure 6, the results of measuring the packet error rate at each point in the plant are displayed as a map. In this embodiment, the map is represented as a grayscale chart, but it may also be represented as a color chart such as RGB. Assume that the lower the error rate measured at each location on the map in Figure 6, the closer the corresponding point is to black. In other words, the better the radio wave reception, the closer the corresponding point is to black. Conversely, assume that the higher the error rate, the closer the corresponding point is to white. In other words, the worse the radio wave reception, the closer the corresponding point is to white.

[0051] The radio waves used to transmit packets are transmitted from a transmitter 20 located in the plant. The radio waves are reflected or diffracted by structures 40, including buildings and equipment, located within the plant. The radio waves are also blocked or attenuated by structures 40. As a result, the reception of radio waves at each location within the plant is determined by the arrangement or shape of structures 40. For example, if there are no structures 40 between the transmitter 20 and the radio wave measurement location, the reception of radio waves at that measurement location will be good. On the other hand, if there are structures 40 between the transmitter 20 and the radio wave measurement location, the reception of radio waves at that measurement location will be poor. Even if there are structures 40 between the transmitter 20 and the radio wave measurement location, there may be measurement locations where the reception of radio waves is good due to the effects of reflection or diffraction.

[0052] In the wireless communication system 1 according to this embodiment, the site survey device 10 can acquire the results of radio wave measurements taken by the receiver 30 as it moves to multiple locations. By measuring radio waves while the receiver 30 moves, the site survey device 10 can acquire the radio wave measurement results as a line rather than as points. As the radio wave measurement results are acquired as a line, the distribution of radio wave reception conditions at each location along the path the receiver 30 moves is visualized in a map representing the packet error rate measurement results, as illustrated in Figure 6. Furthermore, by measuring radio waves while the receiver 30 moves, the site survey device 10 can acquire measurement results over a wide area in a short time. Acquiring measurement results over a wide area makes it easier to find locations with good radio wave reception conditions.

[0053] <Example of a site survey procedure> The control unit 14 of the site survey device 10 may execute a site survey method including an example procedure in the flowchart illustrated in Figure 7. The site survey method may be implemented as a site survey program to be executed by the processor constituting the control unit 14. The site survey program may be stored on a non-temporary computer-readable medium.

[0054] The control unit 14 acquires the radio wave measurement results from the receiver 30 using the acquisition unit 12 (step S1). The control unit 14 acquires the radio wave measurement location information from the receiver 30 using the acquisition unit 12 (step S2). The control unit 14 displays the radio wave measurement results in association with the measurement location information (step S3). Specifically, the control unit 14 generates a map that displays the measurement results in association with the measurement location information, and displays it on the display device of the site survey device 10 or on an external display device. After executing the procedure in step S3, the control unit 14 finishes executing the procedure in the flowchart of Figure 7.

[0055] (summary) As described above, in the wireless communication system 1 according to this embodiment, the site survey device 10 can acquire the results of measuring radio waves while the receiver 30 moves to multiple locations. By measuring radio waves while the receiver 30 moves, the site survey device 10 can acquire measurement results over a wide area in a short time. Acquiring measurement results over a wide area makes it easier to find locations where radio wave reception is good. In addition, the site survey device 10 can acquire the radio wave measurement results as a line rather than a point, and can visualize the distribution of radio wave reception conditions at each location along the path that the receiver 30 moves along.

[0056] (Other embodiments) The following describes a site survey method according to another embodiment.

[0057] <Measurement location information indicating the measurement range> In the wireless communication system 1 according to this embodiment, the receiver 30 measures radio waves while moving. The receiver 30 may be configured to acquire a predetermined number of measurement results while located within a predetermined range.

[0058] The predetermined range may be set such that the difference between each measurement result measured at multiple measurement locations while the receiver 30 is located within the predetermined range is small. Specifically, the range may be set so that the difference between each measurement result falls below a difference threshold defined as a condition for the site survey. When the error rate is calculated as a measurement result, the difference threshold for the error rate may be set to, for example, a few percent. When the signal strength is calculated as a measurement result, the difference threshold for the signal strength may be set to the value of the signal strength when the packet error rate exceeds a set value, for example, several tens of percent. The difference threshold for the signal strength may be set to a value obtained by multiplying the maximum measurable signal strength by a predetermined coefficient. The predetermined coefficient may be, for example, a value of a few percent or less. The difference thresholds for the error rate or signal strength are not limited to these examples and may be set to other values ​​as appropriate.

[0059] The predetermined number may be a number determined as a necessary condition to ensure the reliability of the radio wave measurement results, and may be set to, for example, 600 samples or more in order to approximate the results during long-term operation.

[0060] The site survey device 10 can acquire a large number of measurement results within a range where the difference between measurement results is small, thereby ensuring the reliability of the measurement results within that range, while acquiring measurement results over a wide area in a limited time. In other words, the measurement time per unit area of ​​the measurement range is shortened.

[0061] The speed at which the receiver 30 measures radio waves while moving within a predetermined range may be determined such that the value obtained by dividing the time the receiver 30 is located within the predetermined range by the interval at which the transmitter 20 transmits radio waves is greater than or equal to a predetermined number. Specifically, when the receiver 30 moves along a linear path, the time the receiver 30 is located within the predetermined range is calculated as the time from when the path enters the predetermined range until when it leaves the predetermined range.

[0062] The acquisition unit 12 of the site survey device 10 may acquire information that identifies a predetermined range as measurement location information. Specifically, when the receiver 30 measures radio waves while moving between multiple locations, the acquisition unit 12 acquires location information for each of the multiple locations. If multiple locations are included within the predetermined range, the predetermined range is identified by the location information for each of the multiple locations. The control unit 14 of the site survey device 10 may perform processing, such as averaging, on a predetermined number of measurement results measured within the predetermined range.

[0063] The control unit 14 may generate a map that associates the results of processing a predetermined number of measurement results with a predetermined range. The control unit 14 may display the results of processing a predetermined number of measurement results across the entire area corresponding to the predetermined range on the map, or it may display the results of processing a predetermined number of measurement results in only a part of the area corresponding to the predetermined range on the map.

[0064] The control unit 14 may define and set the predetermined ranges described above within the area to be surveyed. The control unit 14 may set the predetermined ranges so that multiple predetermined ranges overlap. The control unit 14 may display the results of processing the predetermined number of measurement results described above in the area where the predetermined ranges do not overlap. The control unit 14 may display the average result of the measurement results corresponding to each predetermined range in the area where the predetermined ranges overlap.

[0065] <<Summary>> As described above, the site survey device 10 can process the measurement results of radio waves at multiple measurement locations by considering the measurement location when the receiver 30 measures radio waves while moving as the measurement range. By processing the measurement results of radio waves at multiple measurement locations as the measurement results of radio waves within a single measurement range, a large number of measurement results can be obtained within a single measurement range even when the receiver 30 is moving while measuring. As a result, the reliability of the measurement results within a single measurement range is ensured.

[0066] <Site survey of radio waves transmitted from multiple locations> When transmitting and receiving radio waves between two points within a plant or similar facility, direct communication between the transmitting and receiving points can be difficult. In such cases, a repeater may be installed between the transmitting and receiving points. A site survey may be conducted to determine the location of the repeater.

[0067] Specifically, a site survey may be performed by installing transmitters 20 at each of the two locations where radio waves are transmitted and received. The receiver 30 receives radio waves transmitted from the transmitters 20 installed at each of the two locations, measures the radio wave strength or error rate, etc., and outputs it to the site survey device 10. The acquisition unit 12 of the site survey device 10 acquires the measurement results of the radio waves transmitted from the transmitters 20 installed at each of the two locations from the receiver 30. The control unit 14 of the site survey device 10 calculates the location where the reception of radio waves transmitted from the transmitters 20 installed at each of the two locations is good, based on the measurement results of the radio waves transmitted from the transmitters 20 installed at each of the two locations. The location where the reception of radio waves transmitted from each of the two locations is good is suitable as the radio wave transmission location for each of the two locations. Therefore, the control unit 14 may determine the location where the reception of radio waves transmitted from each of the two locations is good as the installation location for the repeater.

[0068] For example, suppose transmitters 20 are installed at the first and second locations. The acquisition unit 12 acquires the measurement results of radio waves transmitted from the first and second locations from the receiver 30. The control unit 14 may generate a map representing the measurement results of radio waves transmitted from the first location, as shown in Figure 8A. In Figure 8A, the location of transmitter 20 corresponds to the first location. The control unit 14 may generate a map representing the measurement results of radio waves transmitted from the second location, as shown in Figure 8B. In Figure 8B, the location of transmitter 20 corresponds to the second location.

[0069] In Figures 8A and 8B, the error rate calculated by measuring radio waves at multiple locations while the receiver 30 moves along a road or the like is represented in grayscale. In Figures 8A and 8B, the lower the error rate, i.e., the better the radio wave reception, the darker the color of the point corresponding to that location. Conversely, the higher the error rate, i.e., the worse the radio wave reception, the darker the color of the point corresponding to that location.

[0070] The control unit 14 determines a location where radio wave reception is good in both maps 8A and 8B. Specifically, in maps 8A and 8B, the distribution of radio wave reception is caused by mountains 41 and 42 located between the first and second points. Regions 51 and 52 correspond to locations where radio wave reception is good in both maps 8A and 8B. Referring to Figure 8A, region 51 is an area where radio waves transmitted from the transmitter 20 located at the first point can easily reach through the area between mountains 41 and 42. Referring to Figure 8B, region 52 is an area where radio waves transmitted from the transmitter 20 located at the second point can easily reach through the area between mountains 41 and 42. The control unit 14 may decide on region 51 or 52 as the installation location for the repeater, or it may present region 51 or 52 as a candidate location for installing the repeater.

[0071] The control unit 14 may generate a superimposed map that displays the measurement results of radio waves transmitted from the first location and the measurement results of radio waves transmitted from the second location superimposed on each other. In the superimposed map, the control unit 14 may display the measurement result of the radio waves transmitted from the first location and the radio waves transmitted from the second location, whichever has the worse reception, as the measurement result for each measurement position. By displaying the measurement result of the radio waves with the worse reception, the superimposed map will show locations where the measurement results of radio waves transmitted from both the first and second locations are good.

[0072] The control unit 14 may indicate the installation location of the repeater by superimposing area 51 or 52 on the superimposed map or on the map in Figure 8A or Figure 8B. The control unit 14 may display on the superimposed map locations where the measurement results of the radio waves satisfy the conditions required for radio wave reception. The control unit 14 may display locations where the measurement results of the radio waves satisfy the conditions required for radio wave reception on at least one of the map displaying the measurement results of the radio waves transmitted from the first location or the map displaying the measurement results of the radio waves transmitted from the second location. The conditions required for radio wave reception may include various conditions such as the error rate being less than the error rate threshold, or the radio wave strength being equal to or greater than the radio wave strength threshold.

[0073] The site survey may be performed by installing transmitters 20 at three or more locations. The acquisition unit 12 may acquire measurement results of radio waves transmitted from each transmission point from the receiver 30. The control unit 14 may generate a map displaying the measurement results of radio waves transmitted from each transmission point. The control unit 14 may display on at least one of the superimposed map or the map displaying the measurement results of radio waves transmitted from each transmission point the locations where the measurement results of radio waves transmitted from each transmission point satisfy the conditions required for radio wave reception.

[0074] When conducting a site survey of radio waves transmitted from multiple locations, transmitters 20 may be installed at each location at the same time. In this case, the receiver 30 may measure the radio waves transmitted from each location together. When conducting a site survey of radio waves transmitted from multiple locations, one transmitter 20 may be installed sequentially at each location. Alternatively, fewer transmitters 20 than the number of transmission locations targeted for the site survey may be installed sequentially at each location.

[0075] <<Summary>> As described above, by generating a map that displays the measurement results of radio waves transmitted from multiple locations, the locations where repeaters should be installed between those locations can be easily determined.

[0076] <Example of operation when receiver 30 is assumed to be moving at a constant speed> In the embodiments described above, the receiver 30 is equipped with a location information acquisition unit and outputs its own location information, along with the radio wave measurement results, to the site survey device 10. If the receiver 30 is not equipped with a location information acquisition unit, it may accept input from a user operating the receiver 30 to identify the location of the receiver 30 and output the input location to the site survey device 10. If the site survey device 10 is configured integrally with the receiver 30, the site survey device 10 may accept input from a user operating the site survey device 10 to identify the location of the site survey device 10. The function of the receiver 30 or the site survey device 10 configured integrally with the receiver 30 to accept location input from a user is called an interface.

[0077] Specifically, the interface displays a map such as a topographic map or a layout map of structures covering the area where the site survey is to be conducted. The interface receives input from the user to identify their current location on the displayed map and outputs it to the site survey device 10. The acquisition unit 12 of the site survey device 10 acquires the location entered by the user on the map. The control unit 14 of the site survey device 10 registers the location entered by the user on the map as a mark location. For example, as shown in Figure 9, the control unit 14 may register a mark location 71. The interface receives input from the user to register a mark location and may acquire the position information of the receiver 30 itself from the position information acquisition unit at the time the input to register a mark location is received and output it to the site survey device 10. The acquisition unit 12 of the site survey device 10 may register the current position of the receiver 30 at the time the user inputs the registration of a mark location as the mark location.

[0078] After the user inputs mark position 71 via the interface, the receiver 30 moves to the next mark position 72. The receiver 30 continues to measure radio waves at each position along the movement path as it moves from mark position 71 to mark position 72. In the example in Figure 9, the receiver 30 measures radio waves at measurement positions 711 and 712, respectively, along the movement path from mark position 71 to mark position 72. The receiver 30 does not acquire position information for measurement positions 711 and 712. When the receiver 30 moves to mark position 72, the interface receives input from the user on the displayed map, specifying the current position as mark position 72, and outputs it to the site survey device 10. The acquisition unit 12 acquires the position input by the user. The control unit 14 registers the position input by the user as mark position 72.

[0079] After the user inputs mark position 72 via the interface, the receiver 30 moves to the next mark position 73. The receiver 30 continues to measure radio waves at each position along the movement path as it moves from mark position 72 to mark position 73. In the example in Figure 9, the receiver 30 measures radio waves at each of the measurement positions 721 to 724 along the movement path from mark position 72 to mark position 73. The receiver 30 does not acquire position information for measurement positions 721 to 724. When the receiver 30 moves to the marked position 73, the interface receives input from the user on the displayed map to identify the current position as the marked position 73 and outputs it to the site survey device 10. The acquisition unit 12 acquires the position entered by the user. The control unit 14 registers the position entered by the user as the marked position 73.

[0080] The control unit 14 assumes that the receiver 30 moved at a constant speed along a straight path between the two mark positions. The control unit 14 assumes that measurement positions 711 and 712 between mark position 71 and mark position 72 are positions that divide the line segment connecting mark position 71 and mark position 72 into three equal parts, and calculates the coordinates of measurement positions 711 and 712 based on the coordinates of mark positions 71 and 72. The control unit 14 also assumes that measurement positions 721 to 724 between mark position 72 and mark position 73 are positions that divide the line segment connecting mark position 72 and mark position 73 into five equal parts, and calculates the coordinates of measurement positions 721 to 724 based on the coordinates of mark positions 72 and 73. The control unit 14 associates the coordinates of measurement positions 711, 712, and 721 to 724, calculated based on the coordinates of mark positions 71 to 73, with the measurement results of the radio waves at each measurement position.

[0081] The receiver 30 may output to the site survey device 10 the time when the mark positions were input and the time when the radio waves were measured between the two mark positions. The receiver 30 may also output to the site survey device 10 the time when the radio waves were measured, associating it with the measurement result of the radio waves at that time. The control unit 14 may interpolate the measurement position between the two mark positions based on the time associated with the measurement result of the radio waves. If the times when the radio waves were measured between the two mark positions are not at equal intervals, the control unit 14 may interpolate the measurement position between the two mark positions to match the interval of the times when the radio waves were measured.

[0082] The receiver 30 measures radio waves at each marked location and outputs the radio wave measurement results to the site survey device 10. The control unit 14 associates each marked location with the radio wave measurement results at that location. The control unit 14 generates a map that associates the radio wave measurement results with each marked location and each measurement location.

[0083] In other words, the acquisition unit 12 may acquire the position of the receiver 30 at the start of the period in which the receiver 30 is assumed to be moving at a constant speed as the starting position. The acquisition unit 12 may acquire the measurement results when the receiver 30 measures radio waves at one or more measurement positions along the movement path during the period in which the receiver 30 is assumed to be moving at a constant speed. The acquisition unit 12 may acquire the position of the receiver 30 at the end of the period in which the receiver 30 is assumed to be moving at a constant speed as the ending position. The control unit 14 may calculate the position corresponding to the measurement position between the starting position and the ending position as measurement position information during the period in which the receiver 30 is assumed to be moving at a constant speed by interpolation. The period in which the receiver 30 is assumed to be moving at a constant speed is also called the constant speed movement period.

[0084] The mark position 71 illustrated in Figure 9 corresponds to the starting position. The mark position 73 corresponds to the ending position. The mark position 72 corresponds to the ending position of the constant velocity movement period with mark position 71 as the starting position, and also to the starting position of the constant velocity movement period with mark position 73 as the ending position.

[0085] By having the user input the position where the path of the receiver 30 changes as a mark position and continuing to move the receiver 30, the control unit 14 may set multiple periods of constant-velocity movement consecutively along the bent movement path.

[0086] Furthermore, by having the user input the location as a mark location at the beginning and end of the period during which the receiver 30 remains at that location, the control unit 14 may associate the radio wave measurement results during the period in which the receiver 30 remains at that location with that location.

[0087] <<Example Flowchart>> The control unit 14 may perform a site survey method including the example procedure of the flowchart illustrated in Figure 10, assuming that the receiver 30 is moving at a constant speed.

[0088] When the user inputs a mark position in the receiver 30, the control unit 14 acquires the mark position as the starting position and starts the constant-velocity movement period (step S11). During the constant-velocity movement period, the control unit 14 acquires the measurement results of the radio waves from the receiver 30 (step S12). The control unit 14 may acquire one or more measurement results as the measurement results of the radio waves. When the user inputs the next mark position in the receiver 30, the control unit 14 acquires the mark position as the ending position and ends the constant-velocity movement period (step S13).

[0089] If the receiver 30 measures a radio wave at a measurement position other than the marked position during the constant velocity movement period, the control unit 14 calculates the coordinates of that measurement position by interpolation (step S14). The control unit 14 generates a map that displays the measurement results of the radio waves during the constant velocity movement period in association with the measurement position calculated by interpolation (step S15). After executing the procedure in step S15, the control unit 14 terminates the execution of the procedure in the flowchart of Figure 10.

[0090] <<Summary>> As described above, even if the receiver 30 does not have a position information acquisition unit, the site survey device 10 can determine the measurement position by identifying the mark positions and interpolating by assuming that the receiver 30 moves at a constant speed along a straight path between the mark positions.

[0091] Even if the receiver 30 is equipped with a position information acquisition unit, the site survey device 10 may calculate the measurement position by identifying the mark positions and interpolating by assuming that the receiver 30 moves at a constant speed along a straight path between the mark positions. When position information is measured, for example by GPS, the coordinates are identified with a very large number of digits. Therefore, the data size of the position information can be very large. If the receiver 30 outputs only the position information of the mark positions to the site survey device 10, the data size output from the receiver 30 to the site survey device 10 is reduced.

[0092] <Including vertical movement> The receiver 30 may measure radio waves while moving along the ground surface and acquire position information in the plane along the ground surface. Alternatively, the receiver 30 may measure radio waves while moving in the vertical direction and acquire position information that is specified in a three-dimensional coordinate system.

[0093] The receiver 30 may measure radio waves while moving between floors in a building having multiple floors, for example. When the receiver 30 moves in three-dimensional space, the control unit 14 of the site survey device 10 may generate a three-dimensional map that displays the radio wave measurement results by the receiver 30 in relation to the measurement position in three-dimensional space. The three-dimensional map may be generated, for example, as a collection of two-dimensional maps of multiple floors. The three-dimensional map may also be generated, for example, as a map showing cross-sectional views of multiple floors.

[0094] While embodiments relating to this disclosure have been described above with reference to the drawings, the specific configuration is not limited to these embodiments and may include various modifications without departing from the spirit of this disclosure. [Explanation of Symbols]

[0095] 1. Wireless communication system 10 Site survey device (12: acquisition unit, 14: control unit, 16: storage unit) 20 Transmitters 30 Receiver 40 Structures 41, 42 mountains 51, 52 area 61, 62, 63, 64, 65 measurement position Mark positions 71, 72, 73 711, 712, 721, 722, 723, 724 measurement position

Claims

1. A site survey device that performs a site survey of radio waves transmitted from a transmitter, An acquisition unit that acquires the results of measuring the radio waves transmitted from the transmitter at each of the multiple measurement positions while the receiver is located within a predetermined range, A control unit that generates a map that displays the measurement results of radio waves from the receiver in association with the measurement location information for the plurality of measurement locations. Equipped with, The site survey device is configured such that the predetermined range is set such that the difference between the measurement results measured at each of the plurality of measurement positions located within the predetermined range falls below a judgment threshold defined as a condition for the site survey.

2. The receiver acquires measurement results at a predetermined number of measurement positions while it is located within the predetermined range. The site survey device according to claim 1, wherein the predetermined number is a number determined as a condition necessary to ensure the reliability of the measurement results of the radio waves.

3. The site survey device according to claim 2, wherein the speed at which the receiver moves within the predetermined range to measure radio waves is determined such that the value obtained by dividing the time the receiver is located within the predetermined range by the interval at which the transmitter transmits radio waves is greater than or equal to the predetermined number.

4. The acquisition unit acquires information that identifies the predetermined range as the measurement position information, The site survey apparatus according to claim 2 or 3, wherein the control unit generates the map so associating the results of processing the predetermined number of measurement results with the predetermined range.

5. The acquisition unit is, The position of the receiver at the start of the period during which the receiver is assumed to be moving at a constant speed is obtained as the starting position. The receiver is assumed to be moving at a constant speed during the period in which it measures radio waves, and the measurement results of each measurement are obtained. The position of the receiver at the end of the period during which the receiver is assumed to be moving at a constant speed is obtained as the end position. The site survey apparatus according to any one of claims 1 to 3, wherein the control unit calculates the measurement position between the start position and the end position by interpolation as the measurement position information during a period in which the receiver is assumed to be moving at a constant speed.

6. The acquisition unit acquires measurement results of radio waves transmitted from each of the multiple transmission points. The site survey apparatus according to any one of claims 1 to 3, wherein the control unit generates a superimposed map that displays the measurement results of radio waves transmitted from each of the transmission points superimposed on it.

7. The site survey device according to claim 6, wherein the control unit displays on at least one of the superimposed map or the map displaying the measurement results of radio waves transmitted from each of the transmission points the locations where the measurement results of the radio waves transmitted from each of the transmission points satisfy the conditions required for radio wave reception status.

8. The steps include: moving the receiver to multiple measurement positions while it is located within a predetermined range, and obtaining the results of measuring the radio waves transmitted from the transmitter at each of the multiple measurement positions; The steps include generating a map that displays the measurement results of the radio waves in association with the measurement location information for the plurality of measurement locations, and Make the processor execute it, The predetermined range is set such that the difference between the measurement results measured at each of the plurality of measurement locations located within the predetermined range falls below a judgment threshold defined as a condition for the site survey.

9. A site survey device that performs a site survey of radio waves transmitted from a transmitter moves to multiple measurement locations while the receiver is located within a predetermined range, and acquires the results of measuring the radio waves transmitted from the transmitter at each of the multiple measurement locations. The site survey device generates a map that displays the measurement results of the radio waves in association with the measurement location information for the plurality of measurement locations. Includes, A site survey method in which the predetermined range is set such that the difference between the measurement results measured at each of the plurality of measurement positions located within the predetermined range falls below a judgment threshold defined as a condition for the site survey.

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