Radio device, communication system, route cost calculation method and program

Abstract

To provide a radio device capable of adaptively calculating a route cost with small fluctuation over time without needing any table.SOLUTION: A radio device includes a processing unit and a communication unit. The processing unit calculates a route cost between a first other radio device operating as a gateway terminal and an own radio device operating as a radio terminal based on the number of hops which is the number of relays of a radio signal by a second other radio device that may be interposed as a radio relay device between the first other radio device and the own radio device, and a movement cost reflecting a cumulative value of a movement state of the own radio device. The communication unit transmits first route cost information regarding the route cost to a third other radio device that is selecting a connection destination for wireless communication with the first other radio device. The processing unit calculates the movement cost at a first time based on the speed of the own radio device at the first time and the movement cost before the first time.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to a wireless device, a communication system, a route cost calculation method, and a program. [Background technology]

[0002] Regarding a wireless device that forms a mesh network together with other wireless devices, a method is known in which the moving speed is reflected in the route cost (for example, see Patent Document 1).

[0003] For example, Patent Document 2 describes a method in which link costs corresponding to each element of moving speed and received power value are prepared in advance as a table, and route costs are derived using this table. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-13591 A [Patent Document 2] JP 2011-205556 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the method of Patent Document 1, the continuity of the moving speed of the wireless device is not included in the route cost. Therefore, when the wireless device repeatedly stops and moves, the amount of time-dependent fluctuation in the route cost becomes large, and there is a possibility that the calculated route cost will not match the actual operation.

[0006] Furthermore, in the method of Patent Document 2, it is necessary to prepare in advance a table of route costs corresponding to each element of the moving speed and the received power value.

[0007] One embodiment of the present invention provides a wireless device, a communication system, a route cost calculation method, and a program that can adaptively calculate a route cost that has small fluctuations over time without the need for a table. [Means for solving the problem]

[0008] According to the embodiment, the wireless device includes a processing unit and a communication unit. The processing unit calculates a route cost between the first other wireless device and the wireless device itself, based on a hop count, which is a number of relays of a wireless signal by a second other wireless device that may be present as a wireless relay between the first other wireless device operating as a gateway terminal and the wireless device itself operating as a wireless terminal, and a movement cost reflecting an accumulated value of a movement state of the wireless device itself. The communication unit transmits first route cost information regarding the route cost to a third other wireless device that is currently selecting a connection destination for wireless communication with the first other wireless device. The processing unit calculates the movement cost at the first time based on the speed of the wireless device itself at the first time and the movement cost before the first time. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing an example of a wireless network formed by a plurality of wireless devices in the communication system of the first embodiment. [Diagram 2] FIG. 1 is a diagram showing an example of a basic configuration of a wireless device according to a first embodiment. [Diagram 3] FIG. 4 is a diagram showing a change over time in the movement cost of a wireless device in the first embodiment. [Figure 4] FIG. 4 is a diagram showing a first example of a travel cost calculated by the wireless device of the first embodiment. [Diagram 5] FIG. 11 is a diagram showing a second example of the travel cost calculated by the wireless device of the first embodiment. [Figure 6] FIG. 11 is a diagram showing a third example of the movement cost calculated by the wireless device of the first embodiment. [Figure 7] FIG. 11 is a diagram showing a fourth example of the movement cost calculated by the wireless device of the first embodiment. [Figure 8]5 is a flowchart showing a process flow in which a wireless device of the first embodiment notifies other wireless devices in a wireless network of a route cost of the wireless device itself. [Figure 9] 5 is a flowchart showing the flow of a route selection process of the wireless device according to the first embodiment. [Figure 10] FIG. 13 is a diagram showing an example of the configuration of a wireless device according to a second embodiment. [Figure 11] 10 is a flowchart showing a process flow in which a wireless device of the second embodiment notifies other wireless devices in a wireless network of a route cost of the wireless device itself. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments will be described with reference to the drawings.

[0011] (First embodiment) First, the first embodiment will be described.

[0012] FIG. 1 is a diagram showing an example of a wireless network 110 formed by a plurality of wireless devices 100 in a communication system according to the first embodiment.

[0013] A wireless network 110 is formed by a plurality of wireless devices 100 performing wireless communication with each other. The plurality of wireless devices 100 forming the wireless network 110 can be classified into a gateway terminal, a wireless repeater, and a wireless terminal according to the role in the wireless network 110. Hereinafter, a wireless device 100 that plays the role of a gateway terminal may be referred to as a gateway terminal 103, a wireless device 100 that plays the role of a wireless repeater may be referred to as a wireless repeater 102, and a wireless device 100 that plays the role of a wireless terminal may be referred to as a wireless terminal 101.

[0014] The gateway terminal 103 exists mainly to collect data transmitted from all wireless devices 100 within the wireless network 110 and transfer it to a server (external server) outside the wireless network 110. For this reason, the gateway terminal 103 is provided with a connector for connecting an Ethernet cable or the like, and transfers the collected data to a server installed on the Internet or an intranet using a wired cable connected to the connector.

[0015] The connection between the gateway terminal 103 and a server installed on the Internet or an intranet may be wireless communication.

[0016] The wireless repeater 102 communicates its own data with an external server via the gateway terminal 103, and also relays data of other wireless devices 100 on the same route of the wireless network 110 as the wireless repeater.

[0017] Wireless terminal 101 is the wireless device 100 located farthest from gateway terminal 103 on the route formed within wireless network 110, and communicates its own data with an external server via gateway terminal 103, but does not relay data of other wireless devices 100.

[0018] Whether the wireless device 100 becomes a wireless terminal 101 or a wireless repeater 102 is determined by the position of the wireless device 100 on the route of the wireless network 110 (here, the distance from the gateway terminal 103 as the starting point). On a certain route, the wireless device 100 that is the farthest from the gateway terminal 103 is the wireless terminal 101, and the wireless device 100 located between the wireless terminal 101 and the gateway terminal 103 is the wireless repeater 102. The wireless device 100 can become either the wireless terminal 101 or the wireless repeater 102 depending on the position on the route where it exists.

[0019] In the communication system of the first embodiment, the position of the wireless device 100 on this route is defined as the route cost. The route cost is determined by the wireless device 100 according to its own position so that the route cost is small for the wireless device 100 closer to the gateway terminal 103 and is larger as the wireless device 100 is farther away from the gateway terminal 103.

[0020] In the communication system of the first embodiment configured as described above, the wireless devices 100 wirelessly communicate with each other to form a wireless network 110, and application data required for operation, management applications, and the like of devices such as robots and AGVs equipped with the wireless devices 100 can be transmitted and received from an external server via the gateway terminal 103 through multi-hop communication between the wireless devices 100. Therefore, in the communication system of the embodiment, an area can be formed by relay transmission by the wireless devices 100 without adding a communication infrastructure such as a base station within the service area, and therefore communication services can be enjoyed in a more flexible and wide area.

[0021] 2 is a diagram showing an example of a basic configuration of the wireless device 100. As described above, the wireless device 100 may be a wireless terminal 101, a wireless repeater 102, or a gateway terminal 103.

[0022] The wireless device 100 includes an application processing unit 210 for executing an application (program) for operating a robot, a transmitting unit 201 and a receiving unit 202 for exchanging data required for executing the application with a server installed on the Internet or an intranet, and an antenna 200 for transmitting and receiving a wireless signal in a predetermined frequency band. The wireless device 100 also includes a route selection unit 203 for acquiring route costs of surrounding wireless devices from the received wireless signal and selecting an optimal connection destination based on the route costs, and a route cost calculation unit 204 for determining the route cost of the wireless device itself based on the route costs of the connection destinations. The route cost information of the wireless device itself determined by the route cost calculation unit 204 is included in a predetermined wireless signal and wirelessly transmitted.

[0023] Furthermore, the wireless device 100 of the first embodiment includes a moving speed detection unit 206 for detecting a moving state of the wireless device itself. In the communication system of the first embodiment, the wireless device 100 uses both the calculated moving cost and communication cost for calculating a route cost of the wireless device itself.

[0024] The transmitting unit 201 converts data from the application processing unit 210 into a predetermined radio signal, and transmits it via the antenna 200. Furthermore, the transmitting unit 201 converts the route cost information of the own radio device calculated by the route cost calculation unit 204 into a predetermined radio signal, and transmits it via the antenna 200.

[0025] The receiving unit 202 extracts data from a predetermined wireless signal received via the antenna 200, and passes the data to the application processing unit 210. The receiving unit 202 also extracts route cost information of the surrounding wireless devices from the received predetermined wireless signal, and passes the information to the route selecting unit 203.

[0026] The route selection unit 203 selects a parent wireless device (hereinafter referred to as a parent wireless device) by evaluating the route costs of multiple surrounding wireless devices based on a predetermined criterion. In general, a wireless device compares the route costs obtained from surrounding wireless devices and selects the wireless device that has transmitted the lowest cost as the parent.

[0027] When the wireless device 100 selects a master wireless device, it transmits a predetermined wireless signal to the selected master wireless device to notify it that it is the master wireless device, and also establishes a wireless connection with the master wireless device and sets the gateway terminal as the destination, i.e., executes routing settings. Therefore, the master wireless device is located closer to the gateway terminal on the path of the wireless device.

[0028] The moving speed detection unit 206 is hardware or software for detecting the moving speed of the wireless device itself, and can generally be calculated from position detection by GPS, position detection using BT or indoor wireless LAN, and time information at that time. In the communication system of the first embodiment, the moving speed is not directly reflected in the route cost, but is calculated based on the state variable s t and forgetting factor ω t The state variables are expressed as values ​​normalized by the moving speed. For example, when the wireless device 100 is moving, the state variables are expressed as s t =+1 (moving state), when the wireless device 100 is stopped, s t =-1 (stopped state). Forgetting factor ω t (0<ω t <1) is a value that represents the effect that the movement speed of the wireless device 100 has on the stability of the network, and indicates a value close to 0 when the wireless device 100 moves at a speed at which network stability can be sufficiently ensured, and indicates a value close to 1 when the wireless device 100 moves at a speed at which network stability cannot be sufficiently ensured.

[0029] The movement cost calculation unit 205 calculates the speed information detected by the movement speed detection unit 206, that is, the state variable s t and forgetting factor ω t For example, the movement cost m t The movement cost is calculated based not only on the current (first time) state variables but also on the result of multiplying the past movement cost by a weighting that is an index of network stability. That is, in the communication system of the first embodiment, the movement cost is calculated based not only on the current (first time) movement speed but also on the evaluation result of the past (before the first time) movement speed.

[0030] m t = s t + ω t × m t-1 ...Equation (1) The route cost calculation unit 204 calculates the route cost of the parent wireless device, the cost per unit relay (hop), the movement cost m tThe route cost C of the own wireless device is calculated from the above. Here, the route cost of the parent wireless device is obtained by receiving a wireless signal including the route cost transmitted from the parent wireless device. The cost per unit relay (hop) is a value equivalent to the number of relays starting from the gateway terminal, and is often set in advance taking into account the scale of the network and the network stability required by the application. The route cost of the own wireless device is calculated as C n , the route cost of the parent wireless device is C n-1 If the cost per unit hop is NH, the route cost calculation unit 204 calculates the route cost of the own radio device, for example, as shown in equation (2).

[0031] C n = C n-1 +NH + m t ...Equation (2) In this way, in the communication system of the first embodiment, the travel cost acts to correct the route cost.

[0032] FIG. 3 is a diagram showing a change in the movement cost of the wireless device 100 over time.

[0033] FIG. 3 shows three wireless devices 100 forming a wireless network 110, and illustrates the relative positions of the three wireless devices 100 at times Ta, Tb, Tc, and Td.

[0034] The wireless device 100[2] and the wireless device 100[3] are wirelessly connected to the parent wireless device 100[1]. The wireless device 100[3] is stopped from time Tb to Td, and the wireless device 100[2] is moving in the direction of the arrow from time Tb to Td.

[0035] The movement cost m within the dashed frame indicated by the symbol a1 t is that of the wireless device 100[2], and the movement cost m t is that of the radio 100[3].

[0036] At time Ta, the moving speed detection unit 206 detects that the wireless device 100[2] is moving at a certain speed, and the state variable s t Similarly, in the wireless device 100[2] at time Tb to Td, the state variable s t Here, if it is determined that the moving speed of the wireless device 100[2] from time Ta to time Td is small and does not hinder the formation of a stable network, the moving speed detection unit 206 detects the forgetting factor ω t Set it to a value close to 0 (for example, ω t = 0.2). As a result, the movement cost calculation unit 205 determines the movement cost m t is calculated from equation (1) as shown in FIG.

[0037] On the other hand, if it is determined that the moving speed of the wireless device 100[2] from time Ta to time Td is high and hinders the formation of a stable network, the moving speed detection unit 206 calculates the forgetting factor ω t Set it to a value close to 1 (for example, ω t = 0.8). As a result, the movement cost calculation unit 205 determines the movement cost m t is calculated from equation (1) as shown in FIG.

[0038] A comparison of travel cost calculation example 1 shown in FIG. 4 and travel cost calculation example 2 shown in FIG. 5 reveals that the greater the impact of travel speed on network stabilization, the greater the travel cost at a given time and the greater the amount of fluctuation over time.

[0039] As described in the explanation of the route selection unit 203, a wireless device with a smaller route cost is selected as a parent. Therefore, in the communication system of the first embodiment, a wireless device 100 that hinders network stabilization has a large correction amount due to movement cost. As a result, the route cost of the wireless device 100 tends to be large, and the wireless device 100 is less likely to be selected as a parent by other wireless devices 100.

[0040] On the other hand, at time Ta, the moving speed detection unit 206 detects that the wireless device 100[3] is stopped, and the state variable s t Similarly, in the wireless device 100[3] at times Tb to Td, the state variable s t Here, if it is determined that the moving speed of the wireless device 100[3] is large outside the time period Ta to Td and hinders the formation of a stable network, the moving speed detection unit 206 detects the forgetting factor ω t Set it to a value close to 0 (for example, ω t =0.2). As a result, the movement cost calculation unit 205 calculates the movement cost mt of the wireless device 100[3] from time Ta to Td using equation (1), for example, as shown in FIG.

[0041] In addition, if the downtime of the wireless device 100[3], including the time from Ta to Td, is short, it is determined that the downtime hinders the formation of a stable network. Therefore, the movement cost m t is calculated in the same manner as described above, for example, as shown in FIG.

[0042] On the other hand, if it is determined that the moving speed of the wireless device 100[3] outside the time period Ta to Td is small and does not hinder the formation of a stable network, the moving speed detection unit 206 calculates the forgetting factor ω t Set it to a value close to 1 (for example, ω t = 0.8). As a result, the movement cost calculation unit 205 determines the movement cost m t is calculated from equation (1) as shown in FIG.

[0043] In addition, if the downtime of the wireless device 100[3], including the time from Ta to Td, is long, it is determined that the downtime does not hinder the formation of a stable network. Therefore, the movement cost m t is calculated in the same manner as described above, for example, as shown in FIG.

[0044] By comparing the movement cost calculation example 3 shown in Fig. 6 with the movement cost calculation example 4 shown in Fig. 7, it can be seen that when a mobile station repeatedly moves and stops, the smaller the effect of the movement speed during movement on network stabilization, the smaller the movement cost at a certain time and the smaller the amount of temporal fluctuation. Conversely, it can be seen that the larger the effect of the movement speed during movement on network stabilization, the larger the movement cost at a certain time and the larger the amount of temporal fluctuation. This means that when the wireless device stops from a moving state, the movement cost is calculated reflecting the past movement state of the wireless device 100, so that it can be expected to provide a route cost with small temporal fluctuation regardless of the current movement speed.

[0045] From equation (2), since the movement cost acts to correct the route cost, the fixed station has a sufficiently small movement cost compared to the mobile station because the downtime is long. It can be seen that the correction value of the route cost of the wireless device 100[3] decreases more when the downtime is long and the impact of the moving speed on network stabilization is large.

[0046] As described in the explanation of the route selection unit 203, a wireless device with a smaller route cost is selected as a parent, so in the communication system of the first embodiment, the longer the time that the wireless device is stopped, the smaller the route cost tends to be, and the more likely it is to be selected as a parent by other wireless devices 100. In addition, in a situation where the wireless device 100 repeatedly moves and stops, if the wireless device 100 has a high speed during movement and hinders network stabilization, there is a concern that it will hinder network stabilization even when stopped. In the communication system of the first embodiment, it is possible to reduce the amount of correction due to the movement cost after a certain time has passed since the wireless device 100 stopped, taking into account the amount of influence on network stabilization due to movement. As a result, the route cost of the wireless device 100 tends to be smaller, and the wireless device 100 is more likely to be selected as a parent by other wireless devices 100.

[0047] As described above, in the communication system of the first embodiment, the wireless device 100 detects its own moving speed, calculates the moving cost by combining the detection results of the past moving speed, and can calculate the route cost of the wireless device 100 according to the magnitude of the influence on the network stability. Therefore, in the wireless network 110 using the wireless device 100, the route cost is controlled to an appropriate value according to the moving speed and moving frequency of the wireless device 100, so that it is expected that the network stability can be maintained and improved in a wireless mesh network in which fixed stations and mobile stations are mixed.

[0048] The wireless device 100 constantly maintains its own route cost and periodically transmits it by wireless signal to inform other wireless devices 100 in the wireless network 110. This process will be described with reference to FIG.

[0049] After powering on, the wireless device 100 starts a predetermined wireless method. After that, the wireless device 100 receives wireless signals wirelessly transmitted from surrounding wireless devices, and extracts the route costs of the surrounding wireless devices 100 from the wireless signals. The wireless device 100 compares and evaluates the costs of multiple routes, and selects the wireless device with the smallest route cost as the parent (S101: YES). That is, the wireless device 100 executes route selection or reselection. If the route cost of the surrounding wireless device 100 is greater than the route cost of the wireless device itself, the wireless device 100 does not execute route reselection (S101: NO).

[0050] When the wireless device 100 executes route selection (selection of a parent wireless device) or route reselection (selection of another wireless device), the route cost C n-1 If there is a change, the route cost of the own wireless device is updated (S102).

[0051] In parallel with the process of selecting or reselecting a route (steps S101 and S102), the wireless device 100 calculates a state variable s t and forgetting factor ω t (S103), and combine it with the past travel cost to calculate the current travel cost m t is calculated (S104).

[0052] The wireless device 100 updates the route cost of the wireless device itself using the movement cost, the route cost of the parent wireless device, and the cost of the next hop calculated as above, according to equation (2) (S105).

[0053] The calculation of the travel cost may be performed independently of the route selection decision of the wireless device 100. Therefore, in the wireless device 100 of the first embodiment, the route cost is updated in accordance with changes in the state of the wireless device 100, such as moving or stopped.

[0054] A timer is generally provided so that the wireless device 100 periodically notifies the other wireless devices 100 in the wireless network 110 of the route cost. In this case, the wireless device 100 checks whether the timer has expired, and if it has expired (S106: YES), resets the timer and transmits a predetermined wireless signal including the route cost (S107). If the timer has not expired (S106: NO), the wireless device 100 does not transmit the route cost and returns to the route selection decision.

[0055] Furthermore, when there is a route cost inquiry request from a nearby wireless device, the wireless device 100 may transmit a predetermined wireless signal including the route cost, regardless of whether the timer has expired.

[0056] As described above, in the communication system of the first embodiment, the wireless device 100 can autonomously update the movement cost, so that the state of the wireless device 100 can always be reflected in the route cost regardless of the timing of route selection, and a stable wireless network 110 can be constructed according to the state of the wireless device.

[0057] Next, the route selection process of the wireless device 100 will be described with reference to FIG.

[0058] After being powered on, the wireless device 100 starts a predetermined wireless method. After that, the wireless device 100 receives wireless signals wirelessly transmitted from surrounding wireless devices (S201), and extracts the path costs of the surrounding wireless devices from the wireless signals (S202). The wireless device 100 compares and evaluates the extracted multiple path costs, and selects the wireless device 100 with the smallest path cost as a parent (S203). Then, the wireless device 100 executes a wireless link connection procedure for the parent wireless device 100 according to a predetermined procedure (S204). The wireless device 100 receives the path cost C of the parent wireless device, n-1 If there is a change in, the route cost of the next hop and the route cost of the parent wireless device C n-1 The route cost of the own wireless device is updated based on the above and the movement cost of the own wireless device (S205).

[0059] As described above, in the communication system of the first embodiment, the wireless device collects and compares the route costs from the surrounding wireless devices, and can select the wireless device 100 with the smallest route cost, including the travel cost, at that time as the parent. This makes it possible to build a stable wireless network 110 according to the state of the wireless device 100.

[0060] That is, the communication system of the first embodiment does not need to include a table, and can adaptively calculate a route cost that has small fluctuations over time.

[0061] Second embodiment Next, a second embodiment will be described.

[0062] 10 is a diagram showing an example of the configuration of a wireless device 100 according to the second embodiment. Note that the same components as those in the wireless device 100 according to the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0063] As shown in FIG. 10, the wireless device 100 of the second embodiment further includes a communication quality detection unit 300 that detects the quality of communication with a connection destination, in addition to the configuration of the wireless device 100 of the first embodiment (see FIG. 2).

[0064] The communication quality detection unit 300 measures the communication quality in the wireless link between the master wireless device and the own wireless device. The measured communication quality is indicated, for example, by the received power from the master wireless device and the number of retransmissions of the wireless signal. In the communication system of the second embodiment, the communication quality is calculated based on a forgetting factor ω q Convert to the forgetting factor ω q (0<ω q <1) is a value that represents the effect that the communication quality of the wireless device 100 has on the stability of the network. If the communication quality ensures sufficient network stability, a value close to 0 is calculated, and if the communication quality does not ensure sufficient network stability, a value close to 1 is calculated.

[0065] Calculated forgetting factor ω q is input to the movement cost calculation unit 205 and is reflected as the forgetting coefficient of the movement cost as shown in equation (3).

[0066] m t = s t + ω q ×ω t × m t-1 ...Equation (3) Calculated forgetting factor ω q When the communication quality is good, the correction range of the route cost becomes small, and when the communication quality is poor, the correction range of the route cost becomes large.

[0067] This reflects the fact that even if the moving speed is high, the impact on network stability caused by the moving speed is mitigated if the communication quality is good, and conversely, even if the moving speed is low, the impact on network stability caused by the moving speed is increased if the communication quality is poor.

[0068] As described above, in the communication system of the second embodiment, the wireless device 100 collects and compares the route costs from the surrounding wireless devices, and can select the wireless device 100 with the smallest route cost, including the travel cost, at that time as the parent, so that a stable wireless network 110 can be constructed depending on the state of the wireless device 100.

[0069] FIG. 11 is a flowchart showing a process flow in which the wireless device 100 of the second embodiment notifies the other wireless devices 100 in the wireless network 110 of its own route cost.

[0070] As described above, the wireless device 100 of the first embodiment calculates the state variable s from the moving speed in parallel with the process related to route selection or reselection (steps S101 and S102). t and forgetting factor ω t (S103). In parallel with this, the wireless device 100 of the second embodiment detects the communication quality and converts the communication quality into a forgetting factor ωq (S301). Then, the wireless device 100 of the second embodiment executes a movement cost update process (S104) according to equation (3).

[0071] As described above, in the communication system of the second embodiment, the wireless device 100 autonomously updates the movement cost taking into account the communication cost, and depending on the state of the wireless device 100, it becomes possible to build a more stable wireless network 110.

[0072] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0073] 100...wireless device, 101...wireless terminal, 102...wireless repeater, 103...gateway terminal, 110...wireless network, 200...antenna, 201...transmitter, 202...receiver, 203...route selector, 204...route cost calculator, 205...movement cost calculator, 206...movement speed detector, 210...application processor, 300...communication quality detector.

Claims

1. a processing unit that calculates a path cost between a first other wireless device operating as a gateway terminal and the wireless device itself operating as a wireless terminal according to a hop number that is the number of relays of a wireless signal by a second other wireless device that may be present as a wireless relay device between the first other wireless device operating as a gateway terminal and the wireless device itself operating as a wireless terminal, and a movement cost that reflects an accumulated value of a movement state of the wireless device itself; a communication unit that transmits first route cost information regarding the route cost to a third other wireless device that is selecting a connection destination for wireless communication with the first other wireless device; Equipped with the processing unit calculates the movement cost at a first time based on a speed of the own wireless device at the first time and the movement cost before the first time; Radio.

2. 2. The wireless device according to claim 1, wherein the processing unit updates the current travel cost over time based on the product of the speed of the wireless device at a first time and the travel cost for a certain time period prior to the first time, so that the current travel cost is larger if the travel time is long and is smaller if the travel time is short.

3. 2. The wireless device according to claim 1, wherein the processing unit calculates a first movement cost corresponding to a first time, then acquires a first speed of the wireless device corresponding to a second time, and calculates a second movement cost corresponding to the second time based on the first movement cost and the first speed.

4. The wireless device according to claim 1 , wherein the communication unit receives second route cost information relating to route costs from each of one or more fourth other wireless devices, and selects a connection destination based on the second route cost information.

5. A radio communication system comprising: a radio communication device according to any one of claims 1 to 4; A wireless network is formed by a plurality of the wireless devices wirelessly communicating with each other. Communication systems.

6. A route cost calculation method executed by each of a plurality of wireless devices that form a wireless network by wirelessly communicating with each other, comprising: calculating a route cost between the first other wireless device and the own wireless device according to a number of hops, which is the number of relays of a wireless signal by a second other wireless device that may be present as a wireless relay device between the first other wireless device operating as a gateway terminal and the own wireless device operating as a wireless terminal, and a movement cost reflecting an accumulated value of a moving state of the own wireless device from the past; transmitting first route cost information regarding the route cost to a third other wireless device that is selecting a connection destination for wireless communication with the first other wireless device; Equipped with calculating the route cost includes calculating the movement cost at a first time based on a speed of the own wireless device at the first time and the movement cost before the first time; Route cost calculation method.

7. Each of a plurality of wireless devices that form a wireless network by wirelessly communicating with each other is a processing unit that calculates a path cost between a first other wireless device operating as a gateway terminal and the own wireless device operating as a wireless terminal, in accordance with a hop number that is the number of relays of a wireless signal by a second other wireless device that may be present as a wireless relay device between the first other wireless device operating as a gateway terminal and the own wireless device operating as a wireless terminal, and a movement cost that reflects an accumulated value of a movement state of the own wireless device from the past; a communication unit that transmits first route cost information regarding the route cost to a third other wireless device that is selecting a connection destination for wireless communication with the first other wireless device; It is a program to function as the processing unit calculates the movement cost at a first time based on a speed of the own wireless device at the first time and the movement cost before the first time; program.

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