JP2013066004A - Site survey system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a site survey system that can be easily constructed and by which a communication state in a region where a predetermined system can be constructed can be confirmed quickly.SOLUTION: A survey system 100 is a system for investigating a communication state in a region where a predetermined system can be constructed before the system is constructed. Access points 10a, 10b, ... of the site survey system 100 broadcast testing data for testing the communication state. Each of one or more display terminals 20a, 20b, 20c, 20d, ... in the site survey system 100 has: a reception part 22 receiving the testing data; a measurement part 23 measuring an error rate of the received testing data; and a display part 25 displaying this measurement result as the communication state at a current position.

Description

  The present invention relates to a site survey system.

  The site survey system is a system for investigating in advance what the communication state of the target area where the system is constructed is when a predetermined system that performs wireless communication is constructed. In general, in such a target area, in addition to various devices that use a radio frequency band of about 2.4 GHz (that is, an ISM band) as a wireless communication band, a shield that obstructs wireless communication is installed. ing. For this reason, the communication state in the target area is not uniformly good due to the influence of noise generated by wireless communication of various devices using the ISM band, fading due to multipath, and the position of the shielding object. Therefore, it is very effective to investigate the communication state in the target area in advance before the construction of the predetermined system by the site survey system described above.

  An example of such a site survey system is disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2010-213040). The site survey system according to Patent Literature 1 includes a terminal, an access point that performs wireless communication with the terminal, and a server that communicates with the access point by wire.

  The terminal of Patent Literature 1 acquires only access point information. The server determines the presence or absence of radio wave interference using the access point information collected from the terminal, and outputs information on the access point that is the interference source based on the determination result.

  However, an operator of the site survey system according to Patent Document 1 first installs an access point and a terminal in the target area, and then moves to the server to confirm the interference source from the server. For this reason, in Patent Document 1, in order to grasp the communication state including the interference source, it is necessary to install a server and many terminals in the target area, which is costly and troublesome.

  Also, in Patent Document 1, when a terminal acquires access point information, bidirectional communication including a response request and a response to the request is performed between the terminal and the access point. Therefore, it takes time before the determination of the presence or absence of the interference source is actually performed.

  Therefore, an object of the present invention is to provide a site survey system that can be easily constructed and can quickly confirm a communication state in an area where a predetermined system can be constructed.

  The site survey system is a system for investigating a communication state in an area where a predetermined system can be constructed before the predetermined system is constructed. The site survey system includes a transmission device and one or more display terminals. The transmitting device broadcasts test data for testing the communication state. The one or more display terminals include a reception unit, a measurement unit, and a display unit. The receiving unit receives test data. The measurement unit measures the error rate of the received test data. The display unit displays the measurement result by the measurement unit as a communication state at the current position.

  When the display terminal of this site survey system receives the test data broadcast from the transmitting device, the terminal itself measures the error rate at the current position and displays it as a communication state. Therefore, the operator of the display terminal can grasp the communication state at the current position in real time. In addition, since it is not necessary to provide a separate server for grasping the communication state as in the prior art, the construction of the site survey system is simplified.

  Moreover, it is preferable that the transmission device continues to transmit the test data continuously in units of packets. In this case, the measurement unit of the display terminal measures the error rate every time test data is transmitted for a certain number of packets (for example, every 1000 packets).

  Thereby, the display terminal does not need to receive the data after synchronizing with the transmission start timing of the test data by the transmission device. Accordingly, the error rate measurement time is shortened, and the operator can quickly confirm the communication state.

  Moreover, it is preferable that the measurement unit of the display terminal further measures the reception strength of the test data.

  As a result, not only the error rate but also the received intensity is displayed on the display terminal.

  Furthermore, it is preferable that the measurement unit of the display terminal is configured to further measure the error distribution of the test data.

  As a result, not only the error rate but also the error distribution is displayed on the display terminal.

  Furthermore, the display terminal preferably has a storage unit. The storage unit stores measurement results obtained by the measurement unit.

  Thereby, since the display terminal itself stores the communication state, more detailed data can be accumulated. Therefore, for example, the operator of the display terminal may confirm the measurement result again from the display terminal after measurement by the measurement unit, or may confirm the communication state from the server by connecting the display terminal to a separate server or the like. it can.

  The site survey system may further include a server. In this case, the server is communicably connected to one or more display terminals after completion of the error rate measurement operation. The server acquires a measurement result by the measurement unit from each of one or more display terminals. Then, the server displays each acquired measurement result and / or analyzes the communication state based on the measurement result, and displays the result.

  Thereby, it is also possible to grasp the communication status and the analysis result related to the communication status via the server.

  According to the present invention, the operator of the display terminal can grasp the communication state at the current position in real time. In addition, since it is not necessary to provide a separate server for grasping the communication state as in the prior art, the construction of the site survey system is simplified.

The figure which shows notionally the structure of the site survey system which concerns on one Embodiment of this invention. The block diagram of an access point. The figure which shows notionally the structure of test data. The block diagram of a display terminal. The conceptual diagram of the measurement result data table memorize | stored in the memory | storage part of a display terminal. The example of a screen of the communication state displayed on the display part of a display terminal. The figure which shows the case where a server is connected to the display terminal. A screen example of measurement results and analysis results displayed on the server. The figure for demonstrating operation | movement of the site survey system which concerns on one Embodiment of this invention. The connection example of the server in the modification C. The example of a screen of the measurement result displayed on the display part of the display terminal in the modification D.

  Hereinafter, a site survey system according to an embodiment of the present invention will be described with reference to the drawings.

(1) Overview FIG. 1 is a diagram conceptually showing the configuration of a site survey system 100 according to an embodiment of the present invention. The site survey system 100 is a system that investigates in advance a communication state in an area where the system is constructed before actually constructing a predetermined system using wireless communication. Examples of the predetermined system include a production system used in a product manufacturing process in a factory for manufacturing a product. Accordingly, the site survey system 100 is brought into an area where such a predetermined system can be constructed before the predetermined system is constructed, and performs a site survey. Hereinafter, for convenience of explanation, an area where a predetermined system can be constructed is referred to as “target area OD”.

  The site survey system 100 mainly includes access points (corresponding to transmission devices) 10a, 10b,... And display terminals 20a, 20b, 20c, 20d,. In this embodiment, as shown in FIG. 1, in the target area OD, two access points 10a, 10b,... And four display terminals 20a, 20b, 20c, 20d,. Take the case as an example.

  The numbers of access points and display terminals are not limited to those shown in FIG. For example, the number of access points may be one. Further, the number of display terminals may be any as long as it is one or more.

  The access points 10a, 10b,... Are devices that play the role of a radio base station as the master unit of the display terminals 20a, 20b, 20c, 20d,... It functions as a data transmission device. The installation positions of the access points 10a, 10b,... Are preferably determined so that the radio waves reach the entire target area OD in consideration of the radio wave transmission distances of the access points 10a, 10b,. Accordingly, as shown in FIG. 1, the access points 10a, 10b,... Are installed at a predetermined distance from each other. Note that the installation positions of the access points 10a, 10b,... May be fixed at a predetermined position during the site survey by the site survey system 100, or may be re-installed at another position. good.

  The display terminals 20a, 20b, 20c, 20d,... Have a size and weight that can be moved while being carried by an operator, and perform wireless communication with the access points 10a, 10b,. It is something that can be done. The display terminals 20a, 20b, 20c, 20d,... Are located away from each other and are installed at arbitrary positions in the target area OD.

  In particular, the access points 10a, 10b,... According to the present embodiment continuously check the communication state in the target area OD, that is, perform a site survey while broadcasting test data in the area OD. The display terminals 20a, 20b, 20c, 20d,... Receive the test data and investigate the communication state. Therefore, in the site survey, the access points 10a, 10b,... And the display terminals 20a, 20b, 20c, 20d,. Does not. That is, the access points 10a, 10b,... Only transmit test data to the display terminals 20a, 20b, 20c, 20d,..., And the display terminals 20a, 20b, 20c, 20d,. Only receives this.

  Here, a protocol used in wireless communication between the access points 10a, 10b,... And the display terminals 20a, 20b, 20c, 20d,. IEEE802.11, IEEE802.15, etc. using a wireless communication band of about 2.4 GHz, which is a frequency band that can be freely used without applying for a license or registering use, are not particularly limited.

  Although the access points 10a, 10b,... Have different installation positions, the access points 10a, 10b,... Have the same configuration, and therefore the following description of the configuration of the access points 10a, 10b,. Unless it is necessary to do so, it is simply described as “access point 10”. Similarly, the display terminals 20a, 20b, 20c, 20d,... Are simply referred to as “display terminal 20”.

(2) Configuration of Access Point As shown in FIG. 2, the access point 10 mainly includes a power conversion unit 11, a transmission unit 12, a display unit 13, and a control unit 14.

(2-1) Power Conversion Unit The power conversion unit 11 generates power to be supplied to various components of the access point 10. Specifically, for example, a battery is inserted in the access point 10, and the power conversion unit 11 converts the power from the battery into the power required by each component of the access point 10, and each component To supply. As a result, since the access point 10 does not require a power cable, there is no movement limitation due to the length of the cable, and there is no need to secure power when moving the access point 10 during the site survey. There is no convenience.

  In this case, the power conversion unit 11 is configured by a DC-DC converter, for example, although not shown. The predetermined power after being converted by the power converter 11 is supplied to various components.

  Note that the access point 10 does not necessarily operate using a battery as a power source. For example, IEEE 802.3. It may be configured to be able to operate with an af-compliant PoE power supply (Power over Ethernet (registered trademark)), an AC adapter having a DC jack, or a battery case including a DC plug and a battery.

(2-2) Transmitter The transmitter 12 transmits test data to each display terminal 20 (specifically, 20a, 20b, 20c, 20d,...). The test data is data for testing the communication state in the target area OD. In particular, the transmission unit 12 according to the present embodiment does not send the test data with the display terminals 20a, 20b, 20c, 20d,... As destinations, but displays the display terminals 20a, 20b, If there are 20c, 20d,..., The test data is broadcast so that the terminals 20a, 20b, 20c, 20d,.

  Such a transmission part 12 is comprised by the antenna etc. which were provided in the casing of the access point 10, for example.

  Here, the test data will be described. The test data according to the present embodiment is transmitted continuously in packet units. Each packet is transmitted at regular time intervals (ie, regular cycles). FIG. 3 conceptually shows the structure of this test data. As shown in FIG. 3, the entire test data is divided into a predetermined length, and a header is attached to each divided data. A plurality of bits are assigned as each header, and each header does not include the address of each transmission destination (that is, display terminals 20a, 20b, 20c, 20d,...), But simply “ “To display terminal 20” is included. Further, each header includes information indicating the number of data transmitted in the entire test data, which is the content of the test data following the header. A plurality of bits are also allocated in the content portion of the test data following the header. Note that the test data according to the present embodiment does not include a response request to the access point 10 side or the like because the purpose of the data is achieved as long as it is received by the display device 20. Therefore, the content of the test data only needs to indicate that it is a test for investigating the communication state, not image data or the like.

  The transmission unit 12 continues to transmit the above-described test data continuously in units of packets in the target area OD as long as power is supplied by the power conversion unit 11.

(2-3) Display Unit Although not shown, the display unit 13 is provided so as to be exposed to the outside of the casing of the access point 10, and is configured by a plurality of LEDs, for example. The display unit 13 emits light in a color corresponding to the operation currently performed by the access point 10 in order to notify the operator of the site survey system 100 of the operation performed by the access point 10.

  For example, while the access point 10 continues to transmit test data, the display unit 13 emits green light. Further, while the access point 10 cannot transmit test data due to a failure, the display unit 13 emits red light.

  The display unit 13 may be configured as a display instead of an LED.

(2-4) Control Unit As shown in FIG. 2, the control unit 14 is a microcomputer constituted by a CPU 14 a, a ROM 14 b, and a RAM 14 c, and is connected to various components that constitute the access point 10. A control program for controlling the access point 10 is stored in the ROM 14b. The CPU 14a controls the access point 10 based on a control program stored in the ROM 14b. The RAM 14c functions as a so-called work memory when the CPU 14a executes a control program stored in the ROM 14b.

(3) Configuration of Display Terminal As shown in FIG. 4, the display terminal 20 mainly includes a power conversion unit 21, a reception unit 22, a measurement unit 23, a storage unit 24, a display unit 25, a server communication unit 26, and a control unit. 27.

(3-1) Power Conversion Unit The power conversion unit 21 generates power to be supplied to various components of the display terminal 20. Specifically, a battery is inserted in the display terminal 20, and the power conversion unit 21 converts the power from the battery into the power required by each component of the display terminal 20, and each component To supply.

  Such a power conversion unit 21 is configured by, for example, a transformer, a DC-DC converter, or the like, although not shown.

(3-2) Receiving Unit The receiving unit 22 includes an antenna or the like that has been calibrated for gain, and receives test data that the access point 10 continues to transmit. Specifically, the receiving unit 22 receives test data for each packet.

  In particular, in the present embodiment, with the button operation as a trigger, the receiving unit 22 continues to receive the test data continuously transmitted in units of packets for a certain period of time.

(3-3) Measuring unit The measuring unit 23 measures the error rate of the test data received by the receiving unit 22. In particular, the test data is continuously received in units of packets, but the measurement unit 23 measures the error rate with the fixed number of packets as a group every time a fixed number of packets are transmitted.

  Specifically, the measurement unit 23 counts the number of packets received by the reception unit 22. Then, when the access point 10 finally transmits 1000 packets, how many packets the display terminal 20 has received is stored in the storage unit 24 as a count result. Assuming that the number of packets that can be received is “q”, when the access point 10 finally transmits 1000 packets, the measuring unit 23 determines the ratio “q of the number q of received packets out of 1000 packets. / 1000 "can be the reception success rate. Conversely, the measurement unit 23 calculates a ratio “(1000−q) / 1000” of the number “1000−q” obtained by subtracting the number q of packets received from 1000 packets to 1000 packets as an error rate. Can do. That is, the measurement unit 23 calculates the error rate based on the constant packet number and the count result when the test data continuously transmitted in units of packets reaches the constant packet number, so Measure the error rate. Therefore, for example, the test data for 1000 packets should be sent continuously from the access point 10, but when only the test data for 955 packets is actually received, the error rate is “(1000−955) / 1000 = 45/1000”.

  Here, a method of measuring the error rate by the measurement unit 23 will be described in detail. The measurement unit 23 identifies the number of the test data transmitted from the test data header of one received packet, and if it can be identified, the test data can be received normally. Count as a thing. When the receiving unit 22 newly receives test data for one packet, the measuring unit 23 similarly identifies the number of the test data transmitted from the header of this packet.

  When the measurement unit 23 can determine that the newly received test data is sent next to the previously received test data, the data for two packets sent continuously It can be seen that the test data could be received continuously. Therefore, the error rate at this time is “0/2”. That is, since the number of transmitted packets is “2” and the number of received packets is “2”, the number of errors indicating the number of packets that could not be received is “0”.

  However, if the measurement unit 23 determines that the newly received test data is not sent next to the test data received last time, the measurement data 23 It can be determined that the reception has failed. In this case, the measurement unit 23 includes information on what number of newly received test data is transmitted, information on what number of previously received test data is transmitted, and And the number of test data packets that should have been sent between them. If it can be assumed that one packet of test data is sent between the newly received test data and the previously received test data, the error rate at this time is “1/3”. " That is, the number of transmitted packets is “3”, and the number of errors indicating the number of packets that could not be received is “1”.

  In the above description, the error rate at each time point is described as “temporarily” in order to help understanding the error rate measurement method. However, since the error rate according to the present embodiment is calculated only after a certain number of packets are transmitted, the above description does not indicate that the error rate is measured every time each packet is received.

  The error rate measurement operation described above is started when an error rate measurement instruction is given by an operator via a start button b1 (described later) on the display terminal 20. For example, when the measurement unit 23 measures the error rate by collecting test data of, for example, 1000 packets sent continuously, the measurement unit 23 temporarily ends the error rate measurement operation.

  Furthermore, the measurement unit 23 measures the reception strength of the test data. Specifically, the measurement unit 23 measures the induced voltage of the antenna as the electric field strength in the antenna that is a component of the reception unit 22.

  Further, the measurement unit 23 may further measure an error distribution in addition to the above-described measurement of the error rate and reception intensity. When measuring the error distribution, the measurement unit 23 measures the error distribution based on information such as what number of the received packet is transmitted, as in the error rate measurement. For example, a case where test data for 100 packets is continuously transmitted from the access point 10 and the 100 packets are collected is taken as an example. When the test data of the first received packet is identified as being sent 251st, the measurement unit 23 defines this as relatively “No. 1” (hereinafter referred to as a relative number). The measuring unit 23 also records the test data of each packet received by the receiving unit 22 with the relative number flag so that the recorded data is recorded in the relative numbers “1” to “100”. It can be acquired as data indicating whether or not a packet has been received, whereby an error distribution can be obtained. In particular, since the transmission of the test data by the access point 10 is performed at a constant cycle as described above, the measurement unit 23 can acquire the data of the error distribution in “time” as a result. Become.

  In the present embodiment, the case where the measurement unit 23 measures not only the error rate and the reception intensity of the test data but also the error distribution is taken as an example.

(3-4) Storage Unit The storage unit 24 is configured by a nonvolatile memory. The storage unit 24 stores measurement results (specifically, error rate, reception intensity, error distribution) by the measurement unit 23, and the like.

  FIG. 5 is a diagram conceptually showing how the storage unit 24 stores the measurement results, and is hereinafter referred to as a “measurement result data table 24a”.

  In the measurement result data table 24a, survey number DA1, count result DA2, error rate DA3, maximum reception intensity DA4, minimum reception intensity DA5, and average reception intensity DA6 are associated with each other. The count result DA2 is a result of the measurement unit 23 counting the number q of received packets out of a certain number of packets. The error rate DA3 is an error rate calculated based on the count result DA2 and a certain number of packets. The maximum reception strength DA4, the minimum reception strength DA5, and the average reception strength DA6 indicate the maximum value, the minimum value, and the average value among the reception strengths measured within the certain number of packets.

  Here, although the error rate DA3 is included in the measurement result data table 24a of FIG. 5, since the error rate DA3 can be calculated from the count result DA2, the error rate DA3 is included in the measurement result data table 24a. It does not have to be.

  5 and 6 exemplify reception strengths in which each byte is expressed in hexadecimal, such as “FF” in the columns of reception strengths DA4 to DA6. Is not limited to this. For example, each reception strength may be expressed by a decimal number such as “−72 dBm”.

(3-5) Display Unit The display unit 25 is provided so as to be exposed on the front surface of the display terminal 20. The display unit 25 displays the measurement result by the measurement unit 23 as the communication state at the current position of the display terminal 20. That is, the display unit 25 displays the measurement results in the measurement result data table 24a in the storage unit 24.

  FIG. 6 is a screen example of a communication state displayed by the display unit 25. In the screen example of FIG. 6, the survey number, error rate, average reception strength, maximum reception strength, and minimum reception strength are displayed side by side in the left-right direction at the bottom of the screen. In the upper part of the survey number or the like, an error distribution in which packets that could not be received are represented by white dots as time passes is displayed. Here, the survey No. represents a serial number where the site survey is performed by the site survey system 100. The serial number is not stored in the storage unit 24. However, since the measurement result in the storage unit 24 is fixed-length data, it can be calculated from the stored address.

  In FIG. 6, the total number of packets (that is, 1000 packets) that is the denominator of the error rate is omitted, and only the number of packets that could not be received as the numerator is represented as the error rate. This is because, in this embodiment, the denominator of the error rate is always “1000” packets, so even if the denominator is omitted and only the numerator is represented, it is substantially equivalent to representing the error rate. is there.

  Such a screen example of FIG. 6 is displayed on the display unit 25 after the measurement of the test data for a certain number of packets to be measured, that is, a group of 1000 packets is completed.

  In FIG. 6, the communication state is divided into two parts in the upper and lower directions. For example, this is a state in which the communication states at different positions of the display terminal 20 are displayed in two parts. It is a representation.

  Further, a start button b1 is provided near the right side of the display unit 25 in FIG. The start button b1 is a button for instructing the start of a measurement operation such as an error rate by the measurement unit 23.

(3-6) Server Communication Unit The display terminal 20 according to the present embodiment can communicate with the server 30 via the communication cable 40 as shown in FIG. 7 after the measurement operation such as the error rate described above is completed. Can be connected. The server communication unit 26 serves as a connection interface with the server 30. Specifically, when the server 30 is connected to the display terminal 20, the server communication unit 26 can acquire a response request, a measurement result retrieval request, and the like from the server 30. Further, the server communication unit 26 can make a response to the response request from the server 30 and a response to the measurement result extraction request.

(3-6-1) Server Here, the server 30 will be described. The server 30 is not essential in the present invention, but can be further provided in the site survey system 100.

  The server 30 performs measurement operations such as error rate by one or more display terminals 20a, 20b, 20c, 20d,..., And then completes the display terminals 20a, 20b, 20c, 20d,. Is connected to each display terminal 20a, 20b, 20c, 20d,... When the server 30 acquires the measurement results of the measurement unit 23 from the display terminals 20a, 20b, 20c, 20d,... Via the communication cable 40, the server 30 displays the acquired measurement results as they are, Based on the result, the communication state is analyzed and the result is displayed.

  FIG. 8 shows an example of a screen in which the measurement results of the display terminals 20a, 20b, 20c, 20d,... Are collected and analyzed by the server 30 and displayed on the display unit 31 of the server 30 as an example. Yes. Here, it is assumed that the layout information of the target area OD is input and stored in the server 30 in advance. The server 30 collects the measurement results obtained from the display terminals 20a, 20b, 20c, 20d,..., The measurement results obtained from the display terminals 20a, 20b, 20c, 20d,. The display terminals 20a, 20b, 20c, 20d,. By performing an analysis operation on the distribution and the like, the aggregated measurement results and analysis results are displayed as shown in FIG.

  8, the measurement results received from the display terminals 20a, 20b, 20c, 20d,... Are displayed on the left side of the display unit 31 in the format of Table 31a. In Table 31a, the position information of each display terminal 20a, 20b, 20c, 20d,..., The error rate value and the average reception intensity in the position information are shown. In the error rate values in Table 31a, as in FIG. 6, the denominator is omitted and only the numerator (that is, the number of packets that could not be received) is represented. And on the right side of the display unit 31, the received intensity distribution in the target area OD obtained by analyzing the measurement results (specifically, error rate and average received intensity) received from each display terminal 20, It is represented by the format of the plan view 31b of the target area OD. Here, the reception intensity distribution in the target area OD is represented by a so-called isoline shape in which the positions of the same average reception intensity are connected by a single line.

(3-7) Control Unit The control unit 27 is a microcomputer composed of a CPU 27a, a ROM 27b, and a RAM 27c as shown in FIG. Connected to various components. A control program for controlling the display terminal 20 is stored in the ROM 27b. The CPU 27a controls the display terminal 20 based on a control program stored in the ROM 27b. The RAM 27c functions as a so-called work memory when the CPU 27a executes a control program stored in the ROM 27b.

  Such a control unit 27 performs, for example, updating of the measurement result data table 24a of the storage unit 24, display control of the display unit 25, and the like.

(4) A series of operations by the site survey system FIG. 9 is a diagram showing a series of operations performed by the site survey system 100.

  First, when the access points 10a, 10b,... Are powered on and the power switches of the access points 10a, 10b,... Are turned on (Yes in # 1), the access point 10 transmits test data. Is started (# 2). Then, the access point 10 continues to transmit the data continuously in units of packets every second, for example, irrespective of the operations performed by the display terminals 20a, 20b, 20c, 20d,. 3- # 6).

  When the operator of the site survey system 100 carries the display terminals 20a, 20b, 20c, 20d,... To an arbitrary position in the target area OD, the display terminals 20a, 20b, 20c, 20d,. By pressing the start button b1 in the vicinity of the display unit 25 (Yes in # 7 to 10), measurement operations such as error rates by the display terminals 20a, 20b, 20c, 20d,... Are started (# 11 to 11). # 14).

  The display terminal 20d is later in timing when the start button b1 is pressed than the other display terminals 20a to 20c. Therefore, the display terminal 20d starts the measurement operation such as the error rate later than the other display terminals 20a to 20c (# 14).

  The display terminals 20a, 20b, 20c, 20d,... Continue to receive the packets from the start of the measurement operation until the number of packets transmitted by the access points 10a, 10b,. Then, the number of received packets is counted and the received intensity is measured (# 11 to # 20). Note that the number of packets transmitted by the access points 10a, 10b,... Has not reached 1000 packets, and the display terminals 20a, 20b, 20c, 20d,. Data (specifically, the count number of received packets, reception intensity, etc.) is temporarily held in the RAM 27c. And the display terminals 20a, 20b, 20c, 20d,..., When the number of packets transmitted by the access points 10a, 10b,. The reception intensity (specifically, the maximum reception intensity, the minimum reception intensity, and the average reception intensity) and the error distribution are calculated and stored in the storage unit 24 as measurement results (# 25 to # 28).

  Thereafter, the display terminals 20a, 20b, 20c, 20d,... End the measurement operation and display a screen including the measurement result as shown in FIG. 6 on the display unit 25 (# 29 to # 32). . Since the display terminal 20d has a slower start of measurement operation such as an error rate than the other display terminals 20a to 20c (# 14), the measurement operation is ended and the measurement result is displayed accordingly. It is slower than ~ 20c (# 24, # 28, # 32).

  Further, when the worker moves the positions of the display terminals 20a, 20b, 20c, 20d,..., The above-described series of operations is repeated.

(5) Features (5-1)
The communication state in an area where a predetermined system can be constructed includes the positions of the display terminals 20a, 20b, 20c, 20d,..., The display terminals 20a, 20b, 20c, 20d,. Are different for each position of the display terminals 20a, 20b, 20c, 20d,.

  Further, the conventional site survey method is sometimes carried out using a portable spectrum analyzer or wireless LAN analyzer. In this case, even if the reception intensity or the like in the target area OD can be grasped, it has not been able to grasp until how much wireless communication actually succeeds or fails.

  However, when the display terminals 20a, 20b, 20c, 20d,... Of the site survey system 100 receive test data broadcast from the access point 10, the terminals 20a, 20b, 20c, 20d,. Measures the error rate at the current position and displays this as the communication state. Therefore, the workers of the display terminals 20a, 20b, 20c, 20d,... Can grasp the communication state at the current position (for example, how much wireless communication actually fails) in real time. . In addition, since it is not necessary to provide a separate server for grasping the communication state as in the prior art, the construction of the site survey system is simplified.

(5-2)
Further, the access point 10 of the present embodiment continues to transmit test data continuously in units of packets, and the measurement unit 23 of each display terminal 20a, 20b, 20c, 20d,. Each time the number of packets is transmitted, the error rate is measured. That is, the measurement unit 23 counts the number of received packets, and calculates the error rate using the count result when the number of packets transmitted by the access point 10 reaches a certain number. Thus, the display terminals 20a, 20b, 20c, 20d,... Do not need to receive the data after synchronizing with the transmission start timing of the test data by the access point 10. That is, the display terminals 20a, 20b, 20c, 20d,... Can receive the test data continuously transmitted in units of packets from any timing. And the display terminals 20a, 20b, 20c, 20d,... Start to count from the start of reception by the display terminals 20a, 20b, 20c, 20d,. When this happens, the error rate can be measured. Accordingly, the error rate measurement time is shortened, and the operator can quickly confirm the communication state.

  In addition, the measurement unit 23 of each display terminal 20a, 20b, 20c, 20d,... According to the present embodiment can measure the reception success rate every time a certain number of packets of test data are transmitted. .

(5-3)
In addition, the measurement unit 23 of the display terminals 20a, 20b, 20c, 20d,... According to the present embodiment measures not only the error rate but also the reception strength of the test data. As a result, the display terminal 20a, 20b, 20c, 20d,... Displays the reception intensity in addition to the error rate.

(5-4)
Further, the measurement unit 23 of the display terminals 20a, 20b, 20c, 20d,... According to the present embodiment can measure not only the error rate and reception intensity but also the error distribution of test data. As a result, the display terminals 20a, 20b, 20c, 20d,... Can display not only the error rate and reception intensity but also the error distribution.

(5-5)
In this embodiment, since the measurement results by the measurement unit 23 are stored in the display terminals 20a, 20b, 20c, 20d,... Themselves, more detailed data than storing data in a server or the like. Can be stored. Therefore, the operator of the display terminals 20a, 20b, 20c, 20d,... Checks the measurement results from the display terminals 20a, 20b, 20c, 20d,. The display terminals 20a, 20b, 20c, 20d,... Can be separately connected to a server or the like to check the communication state from the server.

(5-6)
Further, the site survey system 100 according to the present embodiment can be communicably connected to the display terminals 20a, 20b, 20c, 20d,... After completion of the error rate measurement operation via the communication cable 40. An additional server 30 can also be provided. When the server 30 acquires the measurement result by the measurement unit 23 from each display terminal 20a, 20b, 20c, 20d,..., The server 30 can display the measurement result and the analysis result based on the measurement result. Accordingly, it is possible to grasp the communication state and the analysis result related to the communication state via the server 30.

(6) Modifications One embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. For example, the following changes can be considered.

(6-1) Modification A
In the above embodiment, the case has been described in which the display terminals 20a, 20b, 20c, 20d,... Measure and display not only the error rate and reception intensity but also the error distribution. However, the display terminals 20a, 20b, 20c, 20d,... Do not necessarily measure and display the error distribution, and can selectively measure the error distribution.

(6-2) Modification B
In the said embodiment, as shown in FIG. 7, it demonstrated that the server 30 was connected to display terminal 20a, 20b, 20c, 20d, .... However, the site survey system 100 may not be provided with the server 30, but may be configured only by the access points 10a, 10b,... And the display terminals 20a, 20b, 20c, 20d,.

(6-3) Modification C
7 shows a case where the server 30 is directly connected to the display terminals 20a, 20b, 20c, 20d,... Without going through the access points 10a, 10b,. However, as shown in FIG. 10, the server 30 is connected to each of the access points 10a, 10b,... By wire or wireless, so that the display terminal 20a is connected via the access points 10a, 10b,. , 20b, 20c, 20d,...

(6-4) Modification D
In the said embodiment, it demonstrated using FIG. 6 as an example of a screen as which the measurement result by the measurement part 23 is displayed on display terminal 20a, 20b, 20c, 20d, .... However, the display screen example of the measurement result is not limited to FIG. 6, and may be a screen as shown in FIG. 11, for example. In FIG. 11, the number of packets received every elapse of a predetermined time (for example, 1 second), the average reception strength, the maximum reception strength, and the minimum reception strength are represented in different columns.

  In the leftmost column of FIG. 11, the number of packets that can be received, not the number of packets that could not be received out of 1000 packets, is shown. Thereby, the operator can easily grasp the error rate by subtracting the number of packets received from 1000 packets. Therefore, in FIG. 11, the error rate is represented indirectly rather than directly.

(6-5) Modification E
In the above embodiment, it has been described that the screen of FIG. 6 is displayed on the display unit 25 after the measurement for 1000 packets is completed. However, the screen of FIG. 6 may be displayed so that various information is gradually updated as time passes during measurement.

(6-6) Modification F
The display terminal 20 may be a so-called site survey tool dedicated product having only the functions described in the above embodiment, but may have a function other than the site survey tool. For example, when the target area OD is a semiconductor manufacturing factory, the display terminal 20 is used as a site survey tool, and then used to display a process for each lot in a semiconductor manufacturing system built in the target area OD. It may be reused as a terminal.

  In this case, in the ROM 27b of the display terminal 20, a control program for displaying the process for each lot may be stored in addition to the control program as the site survey tool. The display terminal 20 may further be provided with a switching button for switching whether the display terminal 20 is used as a site survey tool or as a tool for displaying a process for each lot.

  Similarly to the display terminal 20, the access point 10 may also be used as a radio base station capable of bidirectional communication in a semiconductor manufacturing system after being used as a site survey system.

(6-7) Modification G
In the above embodiment, it has been described that the server 30 displays the analysis result in addition to the measurement result transmitted from the display terminal 20, as shown in FIG. However, the server 30 may display any one of the measurement result and the analysis result.

10a, 10b, ... Access point 11 Power conversion unit 12 Transmission unit 13 Display unit 14 Control unit 14a CPU
14b ROM
14c RAM
20a, 20b, 20c, 20d,... Display terminal 21 power conversion unit 22 reception unit 23 measurement unit 24 storage unit 24a measurement result data table 25 display unit 26 server communication unit 27 control unit 27a CPU
27b ROM
27c RAM
30 Server 31 Display unit 100 Site survey system

JP 2010-213040 A

Claims (6)

A site survey system for investigating a communication state in an area where the system can be constructed before a predetermined system is constructed,
A transmitter for broadcasting test data for testing the communication state;
1 or more, comprising: a receiving unit that receives the test data; a measuring unit that measures an error rate of the received test data; and a display unit that displays a measurement result by the measuring unit as the communication state at a current position Display terminals,
Comprising
Site survey system. The transmitting device continues to transmit the test data continuously in units of packets,
The measurement unit of the display terminal measures the error rate each time the test data is transmitted for a certain number of packets.
The site survey system according to claim 1. The measurement unit of the display terminal further measures reception strength of the test data;
The site survey system according to claim 1 or 2. The measurement unit of the display terminal can further measure an error distribution of the test data.
The site survey system according to any one of claims 1 to 3. The display terminal is
A storage unit for storing a measurement result by the measurement unit;
Further having
The site survey system according to any one of claims 1 to 4. A server that is communicably connected to one or more of the display terminals after completion of the error rate measurement operation;
Further comprising
The server acquires a measurement result by the measurement unit from each of the one or more display terminals, displays the acquired measurement results, and / or performs an analysis on the communication state based on the measurement results, Display the results,
The site survey system according to any one of claims 1 to 5.

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