WO2018079558A1

WO2018079558A1 - Wireless device

Info

Publication number: WO2018079558A1
Application number: PCT/JP2017/038380
Authority: WO
Inventors: ラバリジョンナヴェルティナ; 史秀児島
Original assignee: 国立研究開発法人情報通信研究機構
Priority date: 2016-10-25
Filing date: 2017-10-24
Publication date: 2018-05-03
Also published as: JP6893631B2; JP2018074262A

Abstract

A wireless device according to an embodiment of the present invention is a wireless device that constitutes a network in which wireless devices belonging thereto are each configured to transmit beacon signals at common time intervals and stop the operation thereof for a predetermined period of time during each beacon signal transmission interval. The wireless device is provided with: a reception unit that receives beacon signals including operation information indicating operation states of other wireless devices belonging to the network; an adjacency information management unit that obtains the operation information of the other wireless devices from the received beacon signals and manages the operation information in association with identifiers of the other wireless devices; and a communication management unit that, when a communication event occurs, determines routing destinations for data transmission in the communication event on the basis of the operation information of the other wireless devices, which is managed by the adjacency information management unit.

Description

Wireless device

The present invention relates to a wireless device that configures a network with a mesh structure.

In communication of a network having a mesh structure, a packet is transmitted to a target wireless device via a wireless device constituting the network. For this reason, how to select a wireless device to be routed, that is, routing processing becomes important.

On the other hand, depending on the network, it may be configured by a battery-driven wireless device. In such a network, dynamic routing processing may be necessary not only from the viewpoint of communication economy but also from the viewpoint of the remaining battery level for driving the wireless device. However, battery-powered wireless devices often perform sleep operations that periodically cease operation due to battery capacity problems, making it difficult to grasp the status of adjacent wireless devices and perform routing processing dynamically. Met.

JP 2013-191358 A

As described above, the conventional wireless device has a problem that it is difficult to perform dynamic routing processing when a mesh-structured network is configured by battery-powered wireless devices. The present invention has been made to solve such a problem, and an object of the present invention is to provide a wireless device that can grasp the status of an adjacent device and perform dynamic routing processing.

The wireless device according to the embodiment is configured such that each of the wireless devices to which the wireless device belongs belongs to a network configured to transmit a beacon signal at a common time interval and to pause operation for a predetermined time during the transmission interval of the beacon signal. A wireless device that is part of the network, and that receives a beacon signal including operation information indicating the operation status of another wireless device belonging to the network, and acquires operation information of the other wireless device from the received beacon signal In the communication event, the adjacent information management unit that manages the operation information in association with the identifier of the other wireless device and the operation information of the other wireless device managed by the adjacent information management unit when the communication event occurs. And a communication management unit that determines a routing destination for transmitting data.

According to the present invention, it is possible to provide a wireless device that can grasp the status of neighboring devices and enable dynamic routing processing.

It is a figure which shows the example of the mesh type network which consists of a radio | wireless apparatus which concerns on embodiment. It is a block diagram which shows the structure of the radio | wireless apparatus which concerns on embodiment. It is a figure which shows the example of the adjacent information of the radio | wireless apparatus which concerns on embodiment. It is a conceptual diagram which shows the beacon electric wave transmission and routing operation | movement in the network which consists of a radio | wireless apparatus which concerns on embodiment in time series. 5 is a flowchart illustrating an example of a routing operation by the wireless device according to the embodiment.

(Network configuration of the embodiment)
Hereinafter, a wireless device according to an embodiment will be described in detail with reference to the drawings. FIG. 1 shows a state of a network formed by the wireless device of the embodiment.

As shown in FIG. 1, the network NW formed by the wireless device of the embodiment has a mesh structure composed of a plurality of wireless devices. The network includes a root device R (“R” in the figure, the same applies hereinafter) that controls the network, and other wireless devices A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, and S exist. The wireless devices constituting the network operate in a state where the power supply capacity such as a battery is limited, and each forms a “hierarchy” (Depth) having the root device R as a vertex. The hierarchy of the wireless device generally indicates the number of hops when a packet is transmitted to the root device R. However, since routing between wireless devices is dynamically determined for reasons of communication economy, the hierarchy of the root device R is “0” and the wireless device D is “2” as shown in FIG. However, it may be possible to communicate with the root device R directly.

Taking the wireless device G in FIG. 1 as an example, the hierarchy is “1”, and as the adjacent wireless devices (communicable wireless devices), the root device R, the wireless devices B, D, F, H, L, M It is shown. The wireless device G can receive packet transmission from the root device R and the wireless devices B, D, F, H, L, and M, and to the root device R, the wireless devices B, D, F, H, L, and M. Packets can be transmitted (routed).

Since the wireless device G communicates with the adjacent route device R and the wireless devices B, D, F, H, L, and M, it is necessary to keep track of the respective operating states, so that the operation of the adjacent wireless device Information indicating the status is acquired and managed from each wireless device. In order to realize this, each wireless device periodically transmits a beacon radio wave (a beacon signal) including information (operation information) indicating its own operation state. That is, the wireless device G receives beacon radio waves from the route device R and the wireless devices B, D, F, H, L, and M, and acquires the respective operating states.

The transmission of beacon radio waves by the wireless device is performed at predetermined time intervals. The transmission interval of beacon radio waves is common to all wireless devices including the root device R. However, the timing for transmitting the beacon radio wave is not always synchronized among all wireless devices including the root device R.

Incidentally, as described above, the wireless device forming the network of the embodiment may be driven by a power source having a limited power source capacity such as a battery. Therefore, the wireless devices A to Q and the wireless device S have a function for suppressing power consumption, except for the route device R that controls the entire network. As one of the functions for suppressing power consumption, there is a hibernation function that puts at least part of the operation of the wireless device into a hibernation state.

In the hibernation state, the transmission / reception function of the wireless device is stopped. Individual radio devices transmit beacon radio waves at a common time interval, but the timing is not synchronized, so beacon radio waves (and transmissions) of neighboring radio devices that are transmitted while they are dormant The target packet itself) cannot be received. Therefore, the radio apparatus according to the embodiment stops the pause function that puts the operation in a pause state at regular time intervals, and adds information indicating the timing to stop the pause function to the beacon radio wave to be transmitted. Thereby, it is possible to notify an adjacent device of the timing at which the device can receive all beacon radio waves.

That is, taking wireless device G as an example, at least while stopping its own sleep function, it receives beacon radio waves from adjacent route device R, wireless devices B, D, F, H, L and M, The timing of these dormant states is acquired, and it is determined at which timing packet transmission is possible. At the same time, the wireless device G puts its own dormant timing on a beacon radio wave and transmits it to the adjacent route device R, wireless devices B, D, F, H, L, and M, and these wireless devices return to themselves. It informs when the packet can be transmitted. As a result, since the wireless device G can know the timing at which the adjacent wireless device can receive radio waves, it is possible to determine which wireless device should be routed when transmitting a packet.

(Radio Device of Embodiment)
Next, the functional configuration of the wireless device that enables routing in the network of the embodiment will be described in detail. As illustrated in FIG. 2, the wireless device 1 according to the embodiment configures a network NW having a mesh structure. And directly connected. The wireless device 1 includes a transmission / reception unit 10 to which an antenna 15 is connected, a communication management unit 20, a self information management unit 30, a self information storage unit 35, an adjacent information management unit 40, and an adjacent information storage unit 45. Note that each of the parent device P, the brother device S, and the child device C has the same configuration as the wireless device 1.

The transceiver 10 is a wireless interface that transmits and receives radio waves in the wireless device of the embodiment. The transmission / reception unit 10 has not only a routing function described below but also a function of performing specific data transmission / reception. The transmission / reception unit 10 has a function of transmitting beacons at predetermined time intervals. In order to avoid a collision with an adjacent wireless device, a so-called CSMA / CA function may be provided.

The communication management unit 20 is a calculation block that performs routing processing in the network NW and data transmission / reception management. The self information management unit 30 is a calculation block that sets or updates its own operation information. The self information storage unit 35 stores the operation information set and updated by the self information management unit 30. The adjacent information management unit 40 is a calculation block that collects and updates operation information of each adjacent wireless device. The adjacent information storage unit 45 stores operation information of each adjacent wireless device.

The operation information is composed of a plurality of elements indicating the operation status of the wireless device. The self-information stored in the self-information storage unit 35 is own operation information, and the adjacent information stored in the adjacent information storage unit 45 is operation information of adjacent wireless devices. The contents of the self information and the adjacent information are common except that the adjacent information includes the address of the corresponding wireless device.

FIG. 3 shows an example of adjacent information (operation information of adjacent devices) stored in the adjacent information storage unit 45. As shown in FIG. 3, the operation information includes, for example, the wireless device hierarchy, the operation period, the beacon interval of the entire operation period, and the number of beacons up to the entire operation period in units of adjacent radio devices.

The transmission / reception unit 10 of the embodiment transmits a beacon radio wave including its own operation information at a predetermined interval in order to enable dynamic routing. The wireless device that has received the beacon radio wave acquires information such as the timing at which the radio device that has transmitted the beacon radio wave is in a dormant state based on operation information included in the beacon radio wave, and uses the information as reference information for routing processing.

As described above, the time interval for transmitting the beacon radio wave is common among the wireless devices, but the timing for transmitting the beacon radio wave is not always synchronized between the wireless devices. Therefore, when receiving beacon radio waves from all adjacent wireless devices, it is necessary to continue the reception state for a certain period. Therefore, the operation information includes information indicating at what timing the corresponding wireless device stops the dormant state (pause function) (is in a continuous reception state).

The operation information will be described in detail with reference to FIG. The hierarchy is information indicating a relative distance based on a metric from the root device R located at the highest position on the network NW in the corresponding neighboring device, and the larger the value, the higher the cost due to the metric required for the root device. It shows that. In the example shown in FIG. 3, devices R, B, F, H, L, and M are listed as neighboring devices, and the layers on the respective networks are shown to be 0, 1, 1, 2, 2, and 2. ing. The device R whose hierarchy is 0 is the highest-level root device.

The operating period is information indicating a period in which the wireless device is in an operating state (a period not in a dormant state) among transmission intervals (periods) of beacons transmitted by the wireless device. The operation period can be represented by a numerical value indicating, for example, how much of the beacon transmission interval is operating (or dormant). In this example, if the operating period is “0.5”, it indicates that only half (1/2) of the beacon transmission intervals are operating, and the remaining period is in a dormant state. In the sleep state of the wireless device, since various functions such as the reception operation are stopped, it is possible to suppress battery consumption. Note that how to represent the operation period is not limited to this example. It may be expressed in a specific unit of time.

The beacon interval of the entire operation period is information indicating the frequency of occurrence of a period (period during which reception is continuously possible) that does not include a dormant state among transmission intervals of beacons transmitted by the wireless device. In the example shown in FIG. 3, the frequency is expressed using the number of beacon radio waves. That is, in the wireless device B of FIG. 3, the beacon interval of the entire operation period is “3”. If the beacon radio wave is transmitted three times, this is a pause state until the next beacon after one transmission. Indicates that it must not be. Similarly, the beacon interval of the entire operation period of the device R is “1”, which indicates that one of the beacon transmissions is not in a dormant state, that is, there is no dormant state.

The number of beacons until the entire operation period indicates the number of beacon signals until the suspension function is canceled after the beacon signal including the operation information. For example, the number of beacons until the entire operation period of the wireless device B is “2”, which indicates that a period that does not include a dormant state appears after two more beacon radio waves are transmitted. Similarly, the number of beacons until the entire operation period of the root device R is “0”, which represents that the route apparatus R is not in a dormant state.

Note that the operation information may include a next operation time indicating a time when the wireless device is operated next time, and a next stop time indicating a time when the radio apparatus is next in the sleep state. This “time” is not limited to hours and minutes, but may be in units of seconds (and in milliseconds). The next operation time and the next stop time may be included in the beacon radio wave, but can be calculated if there is a time when the beacon radio wave is received, the beacon interval of the entire operation period, and the number of beacons until the entire operation period. Therefore, the received wireless device itself may calculate.

(Beacon radio wave in network of embodiment)
Here, with reference to FIG. 4, the transmission aspect of the beacon electric wave of each radio | wireless apparatus in the network of embodiment is demonstrated. FIG. 4 shows an example of transmission timing of beacon radio waves of the route device R and the wireless devices A to D, F to H, L, and M in the network shown in FIG.

As shown in FIG. 4, in the network NW, each of the root device R and the wireless device transmits a beacon radio wave at regular time intervals. For example, when the root device R transmits the beacon radio wave Txr at the reference time t = 0, the root device R transmits the beacon radio wave Txr at regular intervals such as t = t1, t2, t3, t4. Similarly, the wireless device A is not synchronized with the root device R, but transmits a beacon radio wave Txa at a constant time interval ti (between t1 and t2). The same applies to other wireless devices.

As shown in FIG. 4, when the root device R transmits a beacon radio wave Txr at t = 0, the radio devices A, B, C, D, G, and F receive the beacon radio wave (Rxa in the figure). That is, since the wireless devices A, B, C, D, G, and F are adjacent devices of the root device R, it is possible to receive the beacon radio wave of the device R. Similarly, the wireless devices R, B, D, F, H, L, and M can receive the beacon radio wave Txg of the wireless device G.

Note that the beacon radio wave Txa of the radio device A reaches the root device R and the radio device B, but the beacon radio wave Txh of the radio device H reaches the radio devices G and M at the same timing. These are in a positional relationship where beacon radio waves do not reach each other.

In FIG. 4, the broken line indicates a period during which each wireless device is in operation. That is, the root device R is in an operating state for all periods (there is no dormant state), and the wireless device A is in an operating state for a half of the period from immediately after transmitting the beacon radio wave Txa to the next beacon radio wave Txa transmission. . This means that in the operation information shown in FIG. 3, the operation period of the root device R is 1 (all period operation), and the operation period of the wireless device A is 0.5 (only 1/2 of the beacon interval is operating). It corresponds to.

In FIG. 4, FIAF (Full Interval Awake Frequency) corresponds to the beacon interval of the entire operation period in the operation information shown in FIG. For example, the root apparatus R has a beacon interval of “1” for the entire operation period, which indicates that there is no hibernation state (always the entire operation period). Similarly, the wireless device B indicates that one out of three beacon radio waves has no rest state after that and is in the full operation period. That is, there is no rest period after the transmission of the third beacon radio wave Txb (B3) among the three beacon radio wave transmissions (B1, B2, B3), counted from B1 of the wireless device B in FIG. For a period of time), a pause state occurs after the subsequent fourth beacon radio wave Txb (B4).

In the period not surrounded by the broken line in FIG. 4, it cannot be received even if the beacon radio wave arrives. For example, the beacon radio wave Txb of the wireless device B reaches the device A in B1, but is not received because it is not the period indicated by the broken line of the device A. In B3, apparatus A can receive.

That is, all the wireless devices are configured to maintain the operation state continuously without being in a pause state until a beacon radio wave is transmitted a predetermined number of times. Accordingly, since any wireless device has an opportunity to receive the entire period between beacon radio waves, it is possible to receive all beacon radio waves of neighboring devices that can be received.

(Operation of Wireless Device of Embodiment)
Next, the operation of the wireless device in the network of this embodiment will be described in detail with reference to FIGS. The following description is an example of the operation of the wireless device G in FIGS.

The self-information management unit 30 refers to its own operation information stored in the self-information storage unit 35, and gives the communication management unit 20 a timing at which to enter the hibernation state and a period during which the hibernation function to stop the hibernation state should be stopped. Here, as shown in FIG. 4, since the “beacon interval for all operating periods” (FIAF) of the wireless device G is “5”, one out of five transmissions of the beacon radio wave is the next beacon radio wave. It is not in a suspended state until transmission, but is in an operating state for the entire period.

That is, in FIG. 4, the transmission of the beacon radio wave Txg by the wireless device G is shown five times (G1 to G5), but after the first transmission of the first beacon radio wave Txg (G1), there is no pause state and the next The operation state indicated by the broken line continues until the beacon radio wave Txg (G2) is transmitted. For example, the communication management unit 20 performs on / off control of the operation of the transmission / reception unit 10 at a timing indicated by a broken line in FIG. The transmitting / receiving unit 10 can receive beacon radio waves from all adjacent wireless devices during at least the entire operation period as indicated by G1 to G2 (Yes in step 100; hereinafter referred to as “Yes in S100”). .)

The transmission / reception unit 10 receives and decodes the beacon radio waves of the adjacent route device R, wireless devices B, F, H, L, and M, and passes the operation information of each wireless device to the adjacent information management unit 40 (S105).

The adjacent information management unit 40 associates the operation information of each wireless device received from the transmission / reception unit 10 with the address of the wireless device and stores it in the adjacent information storage unit 45 as adjacent information (S110). For example, after transmitting the first beacon radio wave Txg (G1) in FIG. 4, the radio apparatus G first receives the beacon radio wave Txh of the radio apparatus H (point Y). As shown in FIG. 3, according to the operation information included in the beacon of the wireless device H, the beacon interval of the entire operation period is “4”, and the number of beacons until the entire operation period is “4”. This indicates that if the beacon radio wave Txh of the wireless device H is received at the point Y in FIG. 4, one out of four beacons (H1 to H4) includes a period in which there is no sleep state. This corresponds to the fact that a period that does not include a dormant state appears after the fourth beacon radio wave Txh (H4) counted from (a region indicated by a broken line continues until the next beacon radio wave emission). That is, after the operating states (1) to (3) of the wireless device H, a dormant state appears, and in the operating state (4), the next beacon (H5) is transmitted without the dormant state appearing.

Similarly, the wireless device G receives the beacon radio wave Txl from the wireless device L at the point X following the beacon of the wireless device H. As illustrated in FIG. 3, the beacon interval of the entire operation period of the wireless device L is “3”, and the number of beacons until the entire operation period is “3”. This indicates that if the beacon radio wave Txl (L1) of the wireless device L is received at the point X in FIG. 4, one out of three beacons is not in a dormant state, and counted from the point X (L1). This corresponds to the appearance of a period that does not include a dormant state after the third beacon radio wave Txl (L3) is emitted.

The same applies to other wireless devices, and the adjacent information management unit 40 stores adjacent information as shown in FIG.

When a communication event does not occur (No in S115), the transmission / reception unit 10 receives a beacon radio wave from an adjacent wireless device, and the adjacent information management unit 40 updates the adjacent information shown in FIG. 3 (S100 to S110). .

When a communication event occurs (Yes in S115), the communication management unit 20 selects a wireless device that is a counterpart to which a packet is to be transmitted as a routing destination candidate from the viewpoint of communication economy (S120). For example, assume that the wireless device F is selected as a routing destination candidate for the communication event at point a in FIG.

The communication management unit 20 refers to the adjacent information stored in the adjacent information storage unit 45 via the adjacent information management unit 40, and can the wireless device F be received using the operation information of the wireless device F (operation state) (S125). Specifically, based on the adjacent information (operation information) shown in FIG. 3, a timing chart as shown in FIG. 4 is internally generated to determine whether the target wireless device is in operation. .

If the wireless device F is in operation (Yes in S125), the communication management unit 20 determines the wireless device that is the routing destination as the wireless device F (S130), and transmits a packet that is communication data (S135). In the example illustrated in FIG. 4, the wireless device F is in an operating state indicated by a broken line in FIG. Thereafter, the wireless device F transfers the packet to the root device R (b in the figure).

If the wireless device F is not in operation (No in S125), the communication management unit 20 determines whether the packet to be transmitted has a content that allows communication delay (S140). In the example illustrated in FIG. 4, the wireless device F is not operating at the point c.

If the transmission target packet allows a communication delay (Yes in S140), the communication management unit 20 waits for transmission until the wireless device F enters an operating state (S145). That is, since the wireless device F is not in operation in c in the figure, the communication management unit 20 waits for transmission until d in the figure. The communication management unit 20 determines the wireless device F as a routing destination at the timing of point d when the wireless device F is in the operating state (S130), and transmits a packet as communication data (S135). In the example shown in FIG. 4, since the wireless device F is in the operating state indicated by the broken line in d in the figure, the wireless device F is determined as the routing destination. Thereafter, the wireless device F transfers the packet to the root device R (e in the figure).

When the transmission target packet does not allow communication delay (No in S140), for example, when the packet has a flag related to emergency communication, the communication management unit 20 gives up the wireless device F as a routing destination candidate, and others Routing candidates are selected (S150). The communication management unit 20 determines whether or not a new routing candidate is in operation (S125). If not, the communication management unit 20 determines whether to allow communication delay (S140), and the routing destination candidate is determined. Continue processing until In the example shown in FIG. 4, the wireless device B is selected as another candidate at f in the figure, and since the wireless device B is in operation, the wireless device B is determined as the routing destination and the communication data is transmitted. Thereafter, the wireless device B transfers the packet to the root device R (g in the figure).

Thus, according to the wireless device of the embodiment, since its own operation information is transmitted as a regular beacon radio wave and receives a beacon radio wave from an adjacent radio device, the operation information of the radio device is acquired. Even if the wireless devices making up the network are not synchronized, it is possible to grasp the operating status of the wireless devices. That is, even if each wireless device is driven by a battery or the like and has a dormant state, it is possible to determine whether each wireless device is appropriate as a routing destination by acquiring the operating status of each other. Thereby, a dynamic routing process can be enabled.

In addition, according to the wireless device of the embodiment, since each wireless device can set its own FIAF and operation period, it is possible to extend the time in which the device can operate when it is driven by a battery, and the entire network is more stable. Can be

DESCRIPTION OF SYMBOLS 1 ... Radio | wireless apparatus, 10 ... Transmission / reception part, 15 ... Antenna, 20 ... Communication management part, 30 ... Self information management part, 35 ... Self information storage part, 40 ... Adjacent information management part, 45 ... Adjacent information storage part.

Claims

Each of the wireless devices to which the wireless device belongs belongs to a network configured to transmit a beacon signal at a common time interval and to pause operation for a predetermined time during the transmission interval of the beacon signal. Because
A receiving unit that receives the beacon signal including operation information indicating an operation status of another wireless device belonging to the network;
An adjacent information management unit that acquires operation information of the other wireless device from the received beacon signal and manages the operation information in association with an identifier of the other wireless device;
And a communication management unit that determines a routing destination for transmitting data in the communication event based on operation information of the other wireless device managed by the adjacent information management unit when a communication event occurs.
The wireless device according to claim 1, wherein the wireless device to which the wireless device belongs belongs operates once during the transmission interval of the beacon signal once every time the beacon signal is transmitted a predetermined number of times.
The beacon signal includes information indicating how often the continuous operation transmission interval is generated and information indicating transmission timing of the beacon signal during which the continuous operation period occurs. The wireless device according to claim 2.
The wireless communication according to any one of claims 1 to 3, wherein the communication management unit waits for the execution of the communication event when the other wireless device is suspended when the communication event occurs. apparatus.
The communication management unit determines whether or not the communication event allows a delay in communication when the other wireless device is inactive when the communication event occurs, and repeats selection of a routing destination when the communication event is not allowed. The wireless device according to claim 1, wherein the wireless device is a wireless device.