JP2012105183A - Wireless communication terminal, wireless network system, wireless communication path selection program, and wireless communication path selection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless communication terminal capable of selecting a wireless communication path in wireless communication with a partner station with which no direct communication is possible, more appropriately.SOLUTION: A wireless communication terminal 1, for a partner station with which no direct communication is possible, selects a wireless communication path with the partner station among one or more candidates. At this time, the wireless communication terminal 1 calculates a local evaluation value y based on an inter-terminal received signal intensity for each path between adjacent wireless communication terminals in the wireless communication path, for each wireless communication path candidate. The wireless communication terminal 1 sets the local evaluation value to a predetermined upper limit value U when the received signal intensity between the adjacent wireless communication terminals is equal to or more than a predetermined first threshold. Furthermore, the wireless communication terminal 1 calculates an evaluation value Y of the whole wireless communication path by using the local evaluation value calculated for each path between adjacent wireless communication terminals. The wireless communication terminal 1 compares the evaluation value Y calculated for each wireless communication path candidate to select the wireless communication path among those candidates.

Description

  The present invention uses another wireless communication terminal connected to a network as a partner station, and connects the wireless communication terminal that communicates wirelessly with the partner station so that a plurality of wireless communication terminals can communicate with each other wirelessly via the network. A wireless communication route selection program for causing the wireless communication terminal to select a wireless communication route between the wireless network system and the partner station that cannot communicate directly, and a wireless communication route that selects a wireless communication route with the partner station that the wireless communication terminal cannot communicate directly with How to select

  2. Description of the Related Art Conventionally, there is an autonomous distributed wireless network system in which a plurality of wireless communication terminals are connected to each other so as to be capable of wireless communication via a network (see Patent Documents 1 and 2). In this autonomous distributed wireless network system, wireless communication between wireless communication terminals is performed directly or via another wireless communication terminal. In other words, even if a wireless communication terminal is a partner station that cannot communicate directly, it can communicate with this partner station by using another wireless communication terminal as a relay station. For example, the wireless communication terminal A communicates with the wireless communication terminal B that cannot directly communicate using the wireless communication terminal C as a relay station. In this case, it is assumed that the wireless communication terminal C can directly communicate with both the wireless communication terminal A and the wireless communication terminal B.

  Note that the number of relay stations is not limited to one, and a plurality of relay stations may be used.

  The above-described autonomous distributed wireless communication network system includes a surveillance camera system that tracks a suspicious person over a wide area, an earthquake detection system that detects an earthquake (shake) over a wide area, and a temperature distribution that detects a temperature distribution (temperature distribution) over a wide area. It has begun to be used for detection systems.

  In the above-described monitoring camera system, the wireless communication terminal includes a camera that images the monitoring area, an image processing unit that detects a suspicious person by processing a captured image of the camera, and the like as a sensing function. Between the wireless communication terminals, the detected suspicious person is tracked by wireless communication.

  In the above-described earthquake detection system, the wireless communication terminal includes an acceleration sensor or the like that detects the magnitude of ground vibration as a sensing function. The wireless communication terminal receives the time when the other wireless communication terminal detected the shake and the magnitude of the detected shake in wireless communication with another wireless communication terminal, and issued an emergency earthquake warning, tsunami warning, etc. It is used for.

  In the temperature distribution detection system, the wireless communication terminal includes a temperature sensor that detects the temperature of the observation area as a sensing function. Then, the wireless communication terminal receives the temperature detected by the other wireless communication terminal, the time at that time, and the like by wireless communication with the other wireless communication terminal, and uses them for controlling the air conditioner and the like.

JP 2005-323266 A JP 2009-60663 A

  However, it cannot be said that selection of a wireless communication path between wireless communication terminals that cannot directly communicate is sufficient.

  Specifically, the wireless communication path is selected on the assumption that the wireless communication throughput between the wireless communication terminals is proportional to the received signal strength (RSSI (Received Signal Strength Indicator)) during this period. However, in practice, the throughput of wireless communication saturates when the received signal strength increases to some extent. In other words, the throughput of wireless communication is substantially constant when the received signal strength exceeds a certain value (threshold value).

  For this reason, between the wireless communication terminals in which the received signal strength exceeds the above-mentioned threshold in the wireless communication path for performing wireless communication through the relay station because direct communication is not possible (at least between the wireless communication terminals whose one is the relay station) ) Is overestimated, the wireless communication throughput in this wireless communication path is overestimated. As a result, even if there is actually a wireless communication path (candidate) with better throughput, this wireless communication path may not be selected.

  An object of the present invention is to provide a wireless communication terminal, a wireless network system, a wireless communication route selection program, and a wireless communication route selection method that can more appropriately select a wireless communication route in wireless communication with a partner station that cannot communicate directly. There is.

  In order to achieve the above object, the wireless communication terminal of the present invention is configured as follows.

  The wireless communication means uses another wireless communication terminal connected to the network as a partner station and communicates with the partner station wirelessly. In addition, a partner station that cannot directly communicate is communicated through a wireless communication path using a wireless communication terminal other than the partner station connected to the network as a relay station.

  The wireless communication path selection unit selects, from one or more candidates, a wireless communication path with the partner station for the partner station with which the wireless communication unit cannot directly communicate. This wireless communication path candidate may be stored in advance for each partner station. The wireless communication path candidates may be created using the network topology of the wireless network system. In this case, the network topology of the wireless network system may be stored in the wireless communication terminal, and a wireless communication path candidate may be created by limiting the number of relay stations.

  The evaluation value calculation means calculates the evaluation value of the entire wireless communication path for each candidate of the wireless communication path with the partner station with which the wireless communication means cannot communicate directly by the following procedure.

  In a wireless communication path candidate, a local evaluation value based on received signal strength between adjacent wireless communication terminals is calculated. This local evaluation value is set to a predetermined upper limit if the received signal strength between the wireless communication terminals is equal to or greater than a predetermined first threshold. That is, the local evaluation value is saturated at the upper limit if the received signal strength is greater than or equal to the first threshold. Further, the evaluation value calculation means calculates the evaluation value of the entire wireless communication path using the local evaluation value calculated for each adjacent wireless communication terminal.

  The wireless communication path selection means compares the evaluation values calculated for each wireless communication path candidate by the evaluation value calculation means, and selects a wireless communication path from these candidates.

  Therefore, even if there is a wireless communication path in which the received signal strength exceeds the first threshold value in the wireless communication path for performing wireless communication via the relay station because direct communication is not possible, this wireless communication path It is possible to prevent over-evaluation of the wireless communication throughput. This makes it possible to more appropriately select a wireless communication path in wireless communication with a partner station that cannot communicate directly.

  Further, it is desirable that the overall evaluation value for the wireless communication path candidate is calculated by adding not only the above-described local evaluation value but also the communication load factor of the wireless communication terminal existing in the wireless communication path.

  According to the present invention, selection of a wireless communication path in wireless communication with a partner station that cannot directly communicate can be performed more appropriately.

1 is a schematic diagram showing a wireless communication network system. It is a figure which shows the structure of the principal part of a radio | wireless communication terminal. It is a flowchart which shows the process which updates a communication load factor. It is a figure which shows the relationship between received signal strength (RSSI) and a local evaluation value. It is a flowchart which shows a radio | wireless communication path | route selection process.

  Embodiments of the present invention will be described below.

  FIG. 1 is a schematic diagram showing a wireless communication network system. In this wireless communication network system, a plurality of wireless communication terminals 1 (1A to 1H) are connected via a network so as to be capable of wireless communication with each other. In FIG. 1, a line connecting the wireless communication terminals 1 is a link. Communication between the wireless communication terminals 1 can be performed directly or via another wireless communication terminal 1. Here, a wireless communication terminal 1 capable of direct communication is referred to as an adjacent wireless communication terminal 1, and a wireless communication terminal 1 that is not capable of direct communication (a wireless communication terminal 1 communicating via another wireless communication terminal 1) is not adjacent to the wireless communication terminal 1. The communication terminal 1 is called. In addition, a wireless communication terminal 1 that is a target of wireless communication is referred to as a partner station, and a wireless communication terminal 1 that is routed through wireless communication with the partner station is referred to as a relay station. For example, when the wireless communication terminal 1A shown in FIG. 1 communicates with the wireless communication terminal 1E via the wireless communication terminals 1G and 1C, the wireless communication terminal 1E is called a partner station, and the wireless communication terminals 1G and 1C are called relay stations. To tell. The wireless communication terminal 1G is adjacent to the wireless communication terminal 1A and the wireless communication terminal 1C, and the wireless communication terminal 1C is adjacent to the wireless communication terminal 1E and the wireless communication terminal 1G. Since the wireless communication terminal 1A and the wireless communication terminal 1E are not adjacent to each other, wireless communication is performed through a wireless communication path via the wireless communication terminals 1G and 1C.

  Note that wireless communication paths that can be used for wireless communication between the wireless communication terminal 1A and the wireless communication terminal 1E exist in addition to the paths through the wireless communication terminals 1G and 1C.

  Each wireless communication terminal 1 selects a wireless communication path with better wireless communication throughput for a partner station that cannot communicate directly.

  FIG. 2 is a diagram illustrating a configuration of a main part of the wireless communication terminal. The wireless communication terminal 1 includes a control unit 11, a sensor unit 12, a storage unit 13, a timer 14, and a communication unit 15. The control unit 11 controls the operation of each part of the main body. The sensor unit 12 measures an event to be observed by the sensor, processes the output of the sensor, and obtains a measurement result. The sensor unit 12 includes an image sensor, an acceleration sensor, a temperature sensor, and the like according to events to be observed, and measures events to be observed by these sensors.

  The storage unit 13 stores an operation program for operating the apparatus main body, setting data used during operation, and the like. This setting data includes the network topology of the wireless network system. Details of the setting data stored in the storage unit 13 will be described later.

The storage unit 13 has a working area for temporarily storing processing data generated during operation.

  The timer 14 measures the current time. The communication unit 15 performs wireless communication with other wireless communication terminals 1 existing on the network.

  In addition, the wireless communication terminal 1 detects the communication load factor α (x) of the terminal itself and the process of updating the communication load factor α (x) stored in the storage unit 13 at regular intervals. Repeat. The above x is used as a code for identifying the wireless communication terminal 1. For example, the communication load factor of the wireless communication terminal 1A shown in FIG. 1 is represented here as α (A). The communication load factor α (x) referred to here indicates the magnitude of the load on the own terminal caused by the wireless communication in which the own terminal is used as a relay station. Here, the smaller the value of the communication load factor α (x), the smaller the load caused by the wireless communication used as the relay station.

  Further, the wireless communication terminal 1 calculates a local evaluation value y (x1-x2) for evaluating the communication throughput between adjacent wireless communication terminals 1 based on the received signal strength during this period. The above-described x1 and x2 are used as codes for identifying the wireless communication terminal 1. That is, y (x1-x2) is a local evaluation value between the wireless communication terminal x1 and the wireless communication terminal x2. For example, the local evaluation value y between the wireless communication terminal 1A and the wireless communication terminal 1G shown in FIG. 1 is represented by y (1A-1G) here.

  Note that the wireless communication terminal 1 calculates the communication load factor α (x) described above only for its own terminal, but the local evaluation value y (x1-x2) is limited to the case where one of the terminals is the own terminal. First, it can be calculated.

  Here, a method for calculating the communication load factor α (x) and the local evaluation value y (x1−x2) will be described.

  First, a method for calculating the communication load factor α (x) will be described. FIG. 3 is a flowchart showing a process for updating the communication load factor.

The wireless communication terminal 1 resets a counter that counts the relayed packets when the terminal itself becomes a relay station (s1). After resetting the counter at s1, the wireless communication terminal 1 increments the counter every time the terminal becomes a relay station and relays a packet (s3, s4) until a predetermined time (for example, 10 minutes) elapses (s2). ). If the wireless communication terminal 1 determines that a fixed time has elapsed in s2, the wireless communication terminal 1 calculates a communication load factor α (x) using the count value M of the counter (s5). In s5, a value obtained by dividing the count value M by a predetermined value L is calculated as the communication load factor α (x). In particular,
α (x) = count value M / predetermined value L
Calculated by

  The wireless communication terminal 1 updates the communication load factor α (x) stored in the storage unit 13 to the communication load factor α (x) calculated in s5 this time (s6), and returns to s1.

  In this way, the wireless communication terminal 1 updates the communication load factor α (x) of its own terminal with a measured value during the fixed time every fixed time. That is, the wireless communication terminal 1 updates the communication load factor α (x) of its own terminal in substantially real time.

  Next, a method for calculating the local evaluation value y (x1-x2) will be described. FIG. 4 is a diagram illustrating the relationship between the received signal strength (RSSI) and the local evaluation value y.

The wireless communication terminal 1 divides the magnitude of the received signal strength into four, and the calculation formula of the local evaluation value y (x1-x2) is different for each section. Specifically, as shown in FIG. 4, the RSSI size is divided into four by three thresholds th1 to th3 (th1>th2> th3). The threshold th1 corresponds to the first threshold referred to in the present invention, the threshold th2 corresponds to the second threshold referred to in the present invention, and the threshold th3 corresponds to the third threshold referred to in the present invention. As is clear from FIG.
In a range where the received signal strength is greater than or equal to the threshold th1, the local evaluation value y (x1-x2) is calculated as the upper limit value U. Further, when the received signal strength is in the range of the thresholds th1 to th2, the local evaluation value y (x1-x2) is calculated by a proportional expression proportional to the received signal strength. When the received signal strength is in the range of threshold values th2 to th3, the local evaluation value is calculated as the lower limit value L.

  When the received signal strength is less than the threshold th3, the local evaluation value is calculated as 0, and it is determined that the wireless communication terminal 1 is not adjacent (between wireless communication terminals 1 that cannot communicate directly). I have to.

The formula for calculating the local evaluation value y (x1-x2) shown in FIG.
y = U (RSSI ≧ th1)
y = a × RSSI + b (th1 ≧ RSSI ≧ th2)
y = L (th2 ≧ RSSI ≧ th3)
y = 0 (RSSI <th3)
It is.

The constants a and b can be calculated by using the thresholds th1 and th2, the upper limit value U, and the lower limit value L. In particular,
a × th1 + b = U
a × th2 + b = L
The constants a and b can be calculated by solving the above equation.

  The wireless communication terminal 1 stores the threshold values th1 to th3, the upper limit value U, the lower limit value L, and the constants a and b as parameters for calculating the local evaluation value y for the communication throughput between the adjacent wireless communication terminals 1. Stored in the unit 13.

  Next, a wireless communication route selection process in which the wireless communication terminal 1 selects a wireless communication route with a partner station that is not adjacent will be described. FIG. 5 is a flowchart showing the wireless communication route selection process.

  In this wireless network system, a communication path with an adjacent partner station is a direct communication path.

  The wireless communication terminal 1 creates a wireless communication path candidate with the partner station (s11). In s11, using the network topology stored in the storage unit 13, a wireless communication path candidate with the counterpart station is created. At this time, the wireless communication terminal 1 sets an upper limit on the number of relay stations, and creates a wireless communication path candidate within the range. For example, in the wireless communication network system shown in FIG. 1, when the wireless communication terminal 1A creates a wireless communication path candidate with the wireless communication terminal 1E as a partner station, the minimum number of relay stations is two. Therefore, the upper limit of the number of relay stations is set to two, and communication path candidates are created.

In this case, the wireless communication terminal 1A, as a candidate for the wireless communication path,
(1) Wireless communication terminal 1G → wireless communication terminal 1C → wireless communication terminal 1E
(2) Wireless communication terminal 1B → wireless communication terminal 1H → wireless communication terminal 1E
(3) Wireless communication terminal 1F → wireless communication terminal 1D → wireless communication terminal 1E
(4) Wireless communication terminal 1F → wireless communication terminal 1C → wireless communication terminal 1E
Create etc.

  Here, the upper limit of the number of relay stations is set to the minimum number of two, but may be limited to, for example, the minimum number + 1 (that is, three). Further, the wireless communication terminal 1 may store wireless communication path candidates in the storage unit 13 in advance for each counterpart station.

For each wireless communication path candidate created in s11, the wireless communication terminal 1 determines the communication load factor of each relay station located in the wireless communication path and the received signal strength between adjacent wireless communication terminals 1 (between links). Obtain (s12). In s12, for each wireless communication path candidate created in s11, each relay station located in the wireless communication path is requested to notify the communication load factor α (x) and the received signal strength with the adjacent terminal. To do. For example, for the communication path candidate (1) above,
Request the wireless communication terminal 1G to notify the communication load factor α (G) and the received signal strength between the wireless communication terminal 1C and
The wireless communication terminal 1C is requested to notify the communication load factor α (C) and the received signal strength between the wireless communication terminal 1E.

In addition, regarding the communication path candidate (2) above,
Request the wireless communication terminal 1B to notify the communication load factor α (B) and the received signal strength between the wireless communication terminal 1H and
The wireless communication terminal 1H is requested to notify the communication load factor α (H) and the received signal strength between the wireless communication terminal 1E.

  In response to this request, the wireless communication terminal 1 responds to this request by, for each wireless communication path candidate created in s11, the communication load factor of each relay station located in the wireless communication path, and the received signal between adjacent wireless communication terminals 1. Get strength.

  Note that the wireless communication terminal 1 detects the received signal strength between the terminal itself and the adjacent relay station by the terminal itself. In addition, the wireless communication terminal 1 does not request notification of the communication load factor α (x) from the counterpart station.

  For each wireless communication path candidate created in s11, the wireless communication terminal 1 determines whether or not the candidate is inappropriate, and determines that the wireless communication path candidate determined to be inappropriate is subject to subsequent processing. Exclude (s13). In s13, if there is a section where the received signal strength is less than the third threshold th3 between adjacent wireless communication terminals 1 located in the wireless communication path for each wireless communication path candidate, the candidate is not determined. Judge that it is appropriate. In other words, if there is no section where the received signal strength is less than the third threshold th3 between the adjacent wireless communication terminals 1 located in the wireless communication path, it is determined that the candidate is not appropriate.

  The wireless communication terminal 1 calculates a local evaluation value y (x1-x2) between adjacent wireless communication terminals 1 located in the wireless communication path for each wireless communication path candidate determined to be inappropriate in s13 ( s14). As described above, the local evaluation value y (x1-x2) between adjacent wireless communication terminals 1 is calculated from the received signal strength during that time.

  Further, the wireless communication terminal 1 calculates the evaluation value Y of the entire wireless communication path for each candidate of the wireless communication path that is determined to be inappropriate in s13 (s15). In s15, for each adjacent wireless communication terminal 1 located in the wireless communication path, the local evaluation value y (x1-x2) between the wireless communication terminals 1 and one (own terminal side) wireless communication terminal 1 The reciprocal of the product of (1−communication load factor α (x)) is obtained, and the sum is calculated as the evaluation value Y of the entire wireless communication path.

For example, the above-described evaluation value Y of the wireless communication terminal 1A → the wireless communication terminal 1C → the wireless communication terminal 1E, where the wireless communication terminal 1A is a candidate for a wireless communication path with the wireless communication terminal 1E as a partner station,
Y = (1 / (y (A−G) × (1−α (A)))
+ (1 / (y (G−C) × (1−α (G)))
+ (1 / (y (CE) × (1−α (C)))
Calculated by The evaluation value Y of the wireless communication terminal 1B → the wireless communication terminal 1H → the wireless communication terminal 1E is
Y = (1 / (y (A−B) × (1−α (A)))
+ (1 / (y (B−H) × (1−α (B)))
+ (1 / (y (H−E) × (1−α (H)))
Calculated by

  As is apparent from the above description, in s15, for the section where the received signal strength exceeds the threshold th1, the wireless communication path is determined using the local evaluation value y that is the upper limit value U that saturates the wireless communication throughput. The overall evaluation value Y is calculated. Therefore, the evaluation value Y calculated for the wireless communication path having a section in which the received signal strength exceeds the threshold th1 does not become a value that excessively evaluates the wireless communication throughput.

  In addition, a wireless communication path candidate having a section in which the received signal strength is less than the threshold th3 is determined to be inappropriate, and the process for calculating the evaluation value Y of the entire wireless communication path is not executed. Therefore, the processing load on the wireless communication terminal 1 can be suppressed.

  Further, the evaluation value Y of the entire wireless communication path is calculated in consideration of the communication load factor of the wireless communication terminal 1.

  The wireless communication terminal 1 compares the overall evaluation value Y calculated for each wireless communication path candidate in s15, and selects the wireless communication path candidate with the best evaluation value Y as the wireless communication path with the partner station. (S16). In s16, the wireless communication path having the smallest overall evaluation value Y is selected.

  As described above, the wireless communication terminal 1 does not overestimate the wireless communication throughput for the wireless communication path in which the wireless communication terminals 1 having the received signal strength exceeding the threshold value th1 exist. Therefore, the wireless communication terminal 1 can more appropriately select a wireless communication path in wireless communication with a partner station that cannot directly communicate.

  Further, in the configuration in which the wireless communication path selection process shown in FIG. 5 is performed every time when performing wireless communication with the partner station, the time required for communication with the partner station is only the time required for the communication path selection process. Since it increases, it may be executed at the following timing.

  For example, a wireless communication path is stored in the storage unit 13 for each partner station, and when performing wireless communication with the partner station, a response is requested to the partner station through the wireless communication path stored in the storage unit 13. To do. If the response from the partner station is within a predetermined time, communication with the partner station is executed through this wireless communication path. On the other hand, if the response from the partner station is not within the above time, the wireless communication route selection process shown in FIG. 5 is executed, and wireless communication is executed using the wireless communication route selected here. In addition, the wireless communication path for the partner station stored in the storage unit 13 is updated to the wireless communication path selected this time.

  In this way, the wireless communication terminal 1 does not execute the above-described wireless communication route selection process every time wireless communication is performed, so that the load of the wireless communication process in the wireless communication terminal 1 can be suppressed.

1 (1A to 1H) -wireless communication terminal 11-control unit 12-sensor unit 13-storage unit 14-timer 15-communication unit

Claims (8)

With another wireless communication terminal connected to the network as a partner station, wireless communication means for wirelessly communicating with this partner station,
In the wireless communication terminal, the wireless communication means communicates with a wireless communication path that uses a wireless communication terminal other than the remote station connected to the network as a relay station for a remote station that cannot communicate directly.
A wireless communication path selecting means for selecting a wireless communication path with the counterpart station from one or more candidates for a counterpart station that the wireless communication means cannot communicate directly with;
Evaluation value calculation means for calculating an evaluation value of the entire wireless communication path for each candidate of a wireless communication path with a partner station that cannot directly communicate with the wireless communication means,
The evaluation value calculation means calculates a local evaluation value based on received signal strength between adjacent wireless communication terminals in the wireless communication path for each wireless communication path candidate, and is adjacent at this time If the received signal strength between wireless communication terminals is equal to or higher than a predetermined first threshold, the local evaluation value is set to a predetermined upper limit value, and further, a local evaluation value calculated for each adjacent wireless communication terminal is used. To calculate an evaluation value for the entire wireless communication path,
The wireless communication path selection means is a wireless communication terminal that compares evaluation values calculated by the evaluation value calculation means for each wireless communication path candidate and selects a wireless communication path from these candidates.   If the received signal strength between adjacent wireless communication terminals is less than a predetermined first threshold, the evaluation value calculating means calculates the local evaluation value by a linear function using the received signal strength between the adjacent wireless communication terminals as a variable. The wireless communication terminal according to claim 1.   The evaluation value calculation means sets the local evaluation value to a predetermined lower limit value if the received signal strength between adjacent wireless communication terminals is less than a second threshold value that is smaller than the first threshold value. The wireless communication terminal according to 1 or 2.   The evaluation value calculating unit is configured to determine a wireless communication path candidate including a section in which a received signal strength between adjacent wireless communication terminals is less than a third threshold smaller than the second threshold. The wireless communication terminal according to claim 3, wherein the evaluation value is not calculated.   5. The evaluation value calculation unit according to claim 1, wherein the evaluation value calculation unit calculates an evaluation value of the entire wireless communication path by adding a communication load factor of a wireless communication terminal located in the wireless communication path to the local evaluation value. The wireless communication terminal described in 1. A plurality of wireless communication terminals are connected to each other via a network so that they can wirelessly communicate with each other, and between wireless communication terminals that cannot communicate directly, a wireless communication path that uses another wireless communication terminal connected to the network as a relay station In a wireless communication network system for communication,
Each wireless communication terminal
A wireless communication path selection means for selecting a wireless communication path with the partner station from one or more candidates for a partner station that cannot communicate directly;
Evaluation value calculation means for calculating an evaluation value of the entire wireless communication path for each candidate of a wireless communication path with a partner station that cannot directly communicate with the wireless communication means,
The evaluation value calculation means calculates a local evaluation value based on received signal strength between adjacent wireless communication terminals in the wireless communication path for each wireless communication path candidate, and is adjacent at this time If the received signal strength between wireless communication terminals is equal to or higher than a predetermined first threshold, the local evaluation value is set to a predetermined upper limit value, and further, a local evaluation value calculated for each adjacent wireless communication terminal is used. To calculate an evaluation value for the entire wireless communication path,
The wireless communication path selection means compares the evaluation values calculated for each wireless communication path candidate by the evaluation value calculation means, and selects a wireless communication path from these candidates.
Wireless communication network system. Other wireless communication terminals connected to the network as a partner station, provided with wireless communication means for wirelessly communicating with this partner station, for partner stations that cannot be directly communicated, other than the partner station connected to the network A wireless communication path selection program for selecting a wireless communication path with a partner station that cannot communicate directly with a wireless communication terminal, communicating with a wireless communication path using a wireless communication terminal as a relay station,
A wireless communication path selection step for selecting a wireless communication path with the partner station from one or more candidates for the partner station that the wireless communication means cannot communicate directly with,
An evaluation value calculating step for calculating an evaluation value of the entire wireless communication path for each candidate of a wireless communication path with a partner station that cannot directly communicate with the wireless communication means is executed by the wireless communication terminal,
The evaluation value calculating step calculates a local evaluation value based on received signal strength between adjacent wireless communication terminals in the wireless communication path for each wireless communication path candidate, and is adjacent at this time If the received signal strength between wireless communication terminals is equal to or higher than a predetermined first threshold, the local evaluation value is set to a predetermined upper limit value, and further, a local evaluation value calculated for each adjacent wireless communication terminal is used. And calculating an evaluation value of the entire wireless communication path,
The wireless communication route selection step is a step of comparing the evaluation values calculated for each wireless communication route candidate in the evaluation value calculating step and selecting a wireless communication route from these candidates. . Other wireless communication terminals connected to the network as a partner station, provided with wireless communication means for wirelessly communicating with this partner station, for partner stations that cannot be directly communicated, other than the partner station connected to the network A wireless communication route selection method for selecting a wireless communication route with a partner station that cannot communicate directly with a wireless communication terminal that communicates with a wireless communication route that uses a wireless communication terminal as a relay station,
A wireless communication path selection step for selecting a wireless communication path with the partner station from one or more candidates for the partner station that the wireless communication means cannot communicate directly with,
An evaluation value calculating step for calculating an evaluation value of the entire wireless communication path for each candidate of a wireless communication path with a partner station that cannot directly communicate with the wireless communication means,
The evaluation value calculating step calculates a local evaluation value based on received signal strength between adjacent wireless communication terminals in the wireless communication path for each wireless communication path candidate, and is adjacent at this time If the received signal strength between wireless communication terminals is equal to or higher than a predetermined first threshold, the local evaluation value is set to a predetermined upper limit value, and further, a local evaluation value calculated for each adjacent wireless communication terminal is used. And calculating an evaluation value of the entire wireless communication path,
The wireless communication route selection step is a step of comparing the evaluation values calculated for each wireless communication route candidate by the evaluation value calculating step and selecting a wireless communication route from these candidates. .

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