JP4196885B2 - Communication timing control device, communication timing control method, node, and communication system - Google Patents

Description

  The present invention relates to a communication timing control device, a communication timing control method, a node, and a communication system, and more particularly to data communication collision avoidance in a communication system including a plurality of nodes.

  As a system for enabling data communication without a collision between a plurality of nodes distributed in space, there are a TDMA system, a CSMA (CSMA / CA and CSMA / CD) system, and the like (see Non-Patent Document 1). .

  In the CSMA method, a node to be transmitted confirms whether or not another node is communicating based on the presence of a carrier (frequency), and transmits when communication is not being performed. However, in the case of the CSMA system, the number of channels that can be simultaneously communicated decreases.

In the TDMA system, different time slots are assigned to each node, and each node performs data transmission in the time slot assigned to itself. The TDMA system can easily increase the number of channels that can be simultaneously communicated as compared to the CSMA system. . In the TDMA system, when a node used for communication changes dynamically, a certain node (management node) dynamically assigns a time slot to each node.
Matsushita Atsushi, Nakagawa Masao, “Wireless LAN Architecture”, Kyoritsu Shuppan, 1996, p. 47, 53-59, 69

  However, in the case of the TDMA system, if the management node that performs time slot allocation fails, the entire communication system goes down. Also, the process of dynamically reassigning time slots to each node is complicated, and it may not be possible to respond quickly to changes in the situation.

  In the case of the TDMA system, the time slot that each node can transmit is clear. However, if the communication party using the time slot can be arbitrarily determined by the transmitting side, the receiving side cannot transmit to itself. Since it is not known whether or not it is made, it is necessary to always be in a data signal reception waiting state, which consumes power.

  For example, in a communication system from a base station to a terminal, there is intermittent reception as a method for saving power at the terminal. This is to save power by arranging the timing for calling the terminal from the base station, receiving the signal in the reception-on state only during the time when the terminal receives the signal from the base station, and turning off the reception during the rest of the time. This is a method to achieve However, such a power saving method cannot be adopted in a situation where the receiving side does not know when transmission addressed to itself is performed.

  Therefore, a communication timing control device and a communication timing that are highly flexible so that each node can execute effective communication without instructing the communication timing to each node by the management node and that can be expected to save power at the receiving side node. Control methods, nodes and communication systems are desired.

The first present invention is a communication timing control apparatus provided in each of a plurality of nodes constituting the communication system, the receive state variable signal indicating the operation timing of (1) other nodes, its own node a state variable signal communication means for transmitting a state variable signal indicating the operation timing of the intermittently, based on the (2) state variables signal and the basic speed information of the transition from the other node receives the state variable signal communication unit transitions the operation timing of the own node, and the timing determining means for supplying to said state variable signal communication means to generate a state variable signal from the local node that reflects this transition, (3) the state variable signal communication unit state variable signals of other nodes but received, and, based on the operation timing of the node where the timing determining means decides, between the own node and other nodes A stationarity determining unit that determines whether relation of work time is in a stable state, (4) when being determined that the stable state, for each periodic data transmission period determined by the operation timing of the node Data transmission means for transmitting a data signal, (5) data reception means for receiving a data signal from another node when it is determined to be in a stable state, and (6) the timing determination means used for processing Even if the other node sends out the state variable signal, the other node is classified based on whether or not the data signal from the other node reaches the node, and the data transmission period of the other node where the data signal does not reach the node. And a reception on / off control means for turning off the power of the data reception means during at least a part of the period.

  A node according to a second aspect of the present invention includes the communication timing control apparatus according to the first aspect of the present invention.

  A communication system according to a third aspect of the present invention includes a plurality of nodes according to the second aspect of the present invention.

The fourth of the present invention is a communication timing control method, each of the plurality of nodes constituting the communication system is executed, the receive state variable signal indicating the operation timing of (1) other nodes, the own node movement A state variable signal communication step for intermittently transmitting a state variable signal indicating the operation timing; and (2) the state variable signal received from the other node received by the state variable signal communication step and the basic speed information of the transition. shifts the operation timing of the node, and the timing determination step of providing to the state variable signal communication process to generate a state variable signal from the local node that reflects this transition, (3) the state variable signal communication process received state variable signals of the other nodes, and, based on the operation timing of the node where the timing determination process is determined, movement of the own node and other nodes Sakuta A continuity determination step for determining whether or not the ming relationship is in a stable state, and (4) data determined for each periodic data transmission period determined by the operation timing of the own node when it is determined as a stable state. A data transmission step for transmitting a signal; (5) a data reception step for receiving a data signal from another node when it is determined to be in a stable state; and (6) a state used by the timing determination step for processing. Even in the other node that sends the variable signal, the other node is classified depending on whether or not the data signal from the other node reaches the node, and at least the data transmission period of the other node in which the data signal does not reach the node In a part of the period, a reception on / off control step of turning off a power source configured to function as the data reception step is included.

  According to the communication timing control device, the communication timing control method, the node, and the communication system of the present invention, each node can flexibly execute effective communication even when there is no management node, and it is also related to reception and power saving. Can be achieved.

(A) First Embodiment Hereinafter, a first embodiment of a communication timing control device, a communication timing control method, a node, and a communication system according to the present invention will be described with reference to the drawings.

  In the first embodiment, each node generates an impulse signal, and by effectively detecting an impulse signal generated by a node other than itself, the nodes interact with neighboring nodes, and time is distributed autonomously. The slot allocation is determined, and each node can save power as much as possible.

(A-1) Configuration of the First Embodiment FIG. 2 is a block diagram showing an example of node arrangement in the network intended by the first embodiment, and shows the node N1 as a node of interest. In FIG. 2, a solid circle centered on the node of interest N1 indicates a range in which the node N1 can receive an impulse signal described later transmitted by another node. In the example of FIG. 2, the node of interest N1 includes nodes N2, N3, The impulse signal transmitted by N4 can be received. A dotted circle centered on the target node N1 in a range narrower than the solid line circle indicates a range in which the other node and the target node N1 can exchange data signals. In the example of FIG. And data signals.

  FIG. 1 is a block diagram illustrating an internal configuration of each node according to the first embodiment. In FIG. 1, each node includes an impulse signal receiving unit 11, a communication timing calculating unit 12, an impulse signal transmitting unit 13, a tuning determining unit 14, a data communication unit 15, a neighboring node position determining unit 16, and an on / off determining unit 17. Have.

  The impulse signal receiving means 11 receives an impulse signal (destination information is not included) transmitted by a nearby node (for example, another node existing in a range where the transmitted radio wave of the node reaches). Here, the impulse signal is transmitted and received as a timing signal, and has an impulse shape such as a Gaussian distribution shape, for example. The impulse signal reception means 11 is a communication timing calculation means 12, a tuning determination means 14, a neighboring node position, and the received impulse signal itself, a waveform of the impulse signal, or an impulse signal regenerated based on the received impulse signal. The determination unit 16 and the on / off determination unit 17 are given.

The communication timing calculation means 12 forms and outputs a phase signal that defines the communication timing at the node based on the signal given from the impulse signal reception means 11. Here, assuming that the node is the node i and the phase value of the phase signal at the time t is θi (t), the communication timing calculation unit 12 changes the phase signal θi ( t) is changed. The expression (1) is an expression modeling nonlinear vibration, but an expression modeling other nonlinear vibration can also be applied. Further, the phase signal θi (t) can be regarded as a state variable signal of the node.

  Expression (1) represents a rule for changing the rhythm of nonlinear vibration of the phase signal θi (t) of the own node i in accordance with the signal given from the impulse signal receiving means 11. In the equation (1), the first term ω (natural angular frequency parameter) on the right side represents a basic change rhythm (corresponding to “basic speed for transitioning its own operation state”) included in each node, The second term on the right side represents the nonlinear change. Here, the value of ω is unified to the same value throughout the system. The function Pk (t) represents the signal output from the impulse signal receiving means 11 based on the impulse signal received from the neighboring node Nk (k is 2 to 4 in the case of FIG. 2), The function R (θi (t), σ (t)) is a phase response function that expresses a response characteristic that changes its basic rhythm in response to reception of an impulse signal from another node. ).

  Expression (2) represents that the phase response function is defined by a sine wave having a phase value in which random noise is superimposed on the opposite phase of the phase signal θi (t) at time t. Non-linear characteristics in which neighboring nodes are in opposite phases (vibration phase is inverted phase) are realized, and collision avoidance is attempted using the characteristics. That is, an appropriate time relationship (time difference) is formed at the timing when the phase signal value of each node becomes the same value so that the transmission timing of the impulse signal between adjacent nodes does not collide.

  In the equation (2), the constant term π [rad] representing the function σ (t) functions as a non-linear characteristic in which neighboring nodes are out of phase with each other, and the random noise function φ (t) It functions to give random variability to the nonlinear characteristic (the function φ (t) follows, for example, a Gaussian distribution with an average value of 0). Here, the reason why random variability is given to the non-linear characteristic is to deal with a phenomenon that the system does not reach the target stable state (optimal solution) and falls into another stable state (local solution). Because.

  In the equation (2), the form using the sine function is shown as the simplest example of the phase response function R (θi (t), σ (t)), but other functions may be used as the phase response function. good. Further, instead of the constant term π of the function σ (t), a constant λ other than π (0 <λ <2π) may be used. In this case, neighboring nodes are not in antiphase but in different phases. Function.

  The meaning of the above-described function of the communication timing calculation means 12 will be described in detail with reference to FIGS. The state changes shown in FIGS. 3 and 4 are also related to the function of the impulse signal transmission means 13.

  3 and 4 show a relationship formed between a target node (own node) and a neighboring node (other node) j, that is, between each nonlinear vibration rhythm when attention is paid to a certain node i. It shows how the phase relationship of changes with time.

  FIG. 3 shows a case where there is one neighboring node j for the node of interest i. In FIG. 3, the motion of the two mass points rotating on the circle represents the nonlinear vibration rhythm corresponding to the node of interest and the neighboring nodes, and the angle of the mass point on the circle represents the value of the phase signal at that time. Yes. The motion of the point where the rotational motion of the mass point is projected on the vertical or horizontal axis corresponds to the nonlinear vibration rhythm. By the operation based on the equations (1) and (2), the two mass points try to be in opposite phases to each other, and the phases of the two mass points are close to each other in the initial state as shown in FIG. However, with the passage of time, the state (transient state) shown in FIG. 3B changes to a steady state in which the phase difference between the two mass points is approximately π as shown in FIG. 3C.

  Each of the two mass points rotates with the natural angular frequency parameter ω as a basic angular velocity (corresponding to a basic velocity for transitioning its own operation state). Here, when an interaction based on transmission / reception of an impulse signal occurs between nodes, these mass points change (slow / slow) the angular velocities, respectively, and eventually reach a steady state in which an appropriate phase relationship is maintained. This operation can be regarded as forming a stable phase relationship by repelling each other while the two mass points rotate. In the steady state, as will be described later, when each node transmits an impulse signal at a predetermined phase α (for example, α = 0), the transmission timing at each node forms an appropriate time relationship. Will be.

  FIG. 4 shows a case where there are two neighboring nodes j1 and j2 for the node of interest i. Even in the case where there are two neighboring nodes, a stable phase relationship (stability related to temporal relationship) is formed by repelling each other while rotating the respective mass points as described above. The same applies to the case where the number of neighboring nodes is three or more.

  The formation of the above-described stable phase relationship (steady state) has a very adaptive (flexible) property with respect to changes in the number of neighboring nodes. For example, it is assumed that one neighboring node is added when there is one neighboring node with respect to the node of interest and a stable phase relationship (steady state) is formed. The steady state once collapses, but after passing through the transient state, a new steady state in the case where there are two neighboring nodes is reformed. In addition, when a neighboring node is deleted or does not function due to a failure or the like, an adaptive operation is performed in the same manner.

  The communication timing calculation unit 12 outputs the obtained phase signal θi (t) to the impulse signal transmission unit 13, the tuning determination unit 14, the data communication unit 15, and the on / off determination unit 17.

  The impulse signal transmission means 13 transmits and outputs an impulse signal based on the phase signal θi (t). That is, when the phase signal θi (t) reaches a predetermined phase α (0 ≦ α <2π), an impulse signal is transmitted and output. Here, it is preferable that the predetermined phase α is previously unified in the entire system. In the following description, it is assumed that α = 0 is unified throughout the system. In the example of FIG. 3, since the phase signals θi (t) and θj (t) in the steady state are shifted by π at the node i and the node j, the entire system is unified to α = 0. However, the transmission timing of the impulse signal from the node i and the transmission timing of the impulse signal from the node j are shifted by π.

  The tuning determination unit 14 is configured so that mutual adjustment of the transmission timing of the output impulse signal performed between the own node and one or a plurality of neighboring nodes is “transient state” (see FIGS. 3B and 4B) or It is determined which state is the “steady state” (see FIG. 3C or FIG. 4C). The tuning determination means 14 observes the reception timing of the impulse signal (corresponding to the output impulse signal of the other node) and the transmission timing of the impulse signal from its own node, and between the transmission timings of a plurality of nodes that exchange the impulse signal. When the time difference is stable in time, it is determined that the state is “steady state”. A phase signal θi (t) is input to the tuning determination unit 14 as a signal for capturing the transmission timing of the impulse signal from the own node.

  The tuning determination unit 14 performs the tuning determination by executing the following processes (a) to (d), for example.

  (A) The value β of the phase signal θi (t) at the output timing of the signal from the impulse signal receiving means 11 is observed over one period of the phase signal θi (t). As a result of the above observation, the values β of the phase signals θi (t) obtained are set to β1, β2,..., ΒN (0 <β1 <β2 <... ΒN <2π), respectively.

  (B) Based on the value β of the observed phase signal θi (t), the difference between adjacent values (phase difference) Δ1 = β1, Δ2 = β2-β1,..., ΔN = βN−β (N−1) Is calculated.

  (C) The processes of (a) and (b) are performed for each period of the phase signal θi (t), and the amount of change (difference) γ1 = Δ1 (τ + 1) −Δ1 (Τ), γ2 = Δ2 (τ + 1) −Δ2 (τ),..., ΓN = ΔN (τ + 1) −ΔN (τ) are calculated. Here, τ indicates a certain cycle of the phase signal θi (t), and τ + 1 indicates the next cycle of the phase signal θi (t).

  (D) When the above-mentioned change amount γ is smaller than the minute parameter (threshold value) ε, that is, when γ1 <ε, γ2 <ε,. To do.

  Note that a steady state may be determined when the conditions of γ1 <ε, γ2 <ε,..., ΓN <ε are satisfied over M cycles. As the value of M is increased, it is possible to determine “steady state” in a more stable state. Further, the “steady state” may be determined based on a part of the received impulse signals.

  The tuning determination means 14 performs data by using, as a slot signal, a tuning determination signal indicating a determination result and a minimum value β1 of the value β of the phase signal θi (t) at the reception timing of the impulse signal for each period of the phase signal θi (t). Output to the communication means 15.

  The data communication means 15 receives data from other nodes and transmits data that is the transmission source of itself and data that is relayed by the data communication means 15. The data communication means 15 uses the term “time slot” although the data transmission means a time slot (which is not a fixed time interval assigned by the system or the like described later) when the tuning determination signal indicates “steady state”. ) And the transmission operation is stopped when the tuning determination signal indicates “transient state”. The data communication unit 15 performs data reception only during an on determination result period of an on / off determination unit 17 described later.

  The time slot is a period in which the phase signal θi (t) satisfies δ1 ≦ θi (t) ≦ β1-δ2. The start point of the time slot (the value of the phase signal at that time is δ1) is the timing when the transmission of the impulse signal is finished, and the end point of the time slot (the value of the phase signal at that time is β1−δ2). ) Is a timing that is slightly offset δ2 before the timing of the first received impulse signal for each period of the phase signal. δ1 and δ2 are an impulse signal (including both when the source is the own node and the other node) and a data signal (when the source is the own node and the other node) in the wireless space near the node. Phase width corresponding to a very short time to compensate for the absence of both at the same time.

  For example, in the “steady state” as shown in FIG. 3C, the node i starts transmitting the impulse signal from the phase θi of 0, and ends the transmission of the impulse signal before the phase θi becomes δ1. When the phase θi starts to transmit the data signal from δ1 and the phase θi becomes β1−δ2 (where β1≈π), the transmission of the data signal is terminated, and thereafter, until the phase θi becomes 0 again. The transmission of the impulse signal and the transmission of the data signal are stopped. The other node j also performs the same operation based on the phase θj. However, since the phase θi and the phase θj are substantially shifted by π, the transmission operation does not compete. The same operation is performed when the number of nodes is 3 or more, and transmission operations do not compete.

  As described above, the natural angular frequency parameter ω is unified to the same value in the entire communication system (network). If the natural angular frequency ω is unified, it will be easier to enter the steady state than if it is irregularly distributed at each node. Conversely, if the natural angular frequency ω is not unified, an abnormal impulse signal The number of nodes that transmit the message increases, and it is difficult to enter a steady state.

  The neighboring node position determination unit 16 and the on / off determination unit 17 are components provided for power saving at the node.

  The neighboring node position determination means 16 classifies the distance from the own node with respect to the destination node of the received impulse signal. The neighboring node position determination means 16 classifies the distance of the received impulse signal with the counterpart node, for example, either a distance where the data signal (and impulse signal) can be received or a distance where only the impulse signal can be received. The neighboring node position determination means 16 may classify the distance from the own node based on, for example, the peak value of the received power of the received impulse signal, and based on whether the data signal for distance measurement can be effectively communicated. The distance from the own node may be classified. In the description of the operation to be described later, the latter will be described.

  The on / off determination unit 17 holds the determination result of the neighboring node position determination unit 16, and based on the determination result, determines whether to receive a data signal (on) or not (off) for each time slot, and performs data communication. The receiving operation of the means 15 is controlled on / off.

(A-2) Operation of the First Embodiment Next, the operation of the communication system of the first embodiment having a plurality of nodes including the above-described units will be described.

  The communication system of the first embodiment includes (1) formation of a steady state by phase interaction between neighboring nodes, (2) measurement of the distance between neighboring nodes that interact with phase, and (3) transmission and reception of data signals. Operates in a step-by-step procedure.

(1) Formation of Steady State As described above with reference to FIGS. 3 and 4, a phase interaction is performed between neighboring nodes in a range in which impulse signals can be received from each other, and a steady state is formed. Here, in the case of the node arrangement as shown in FIG. 2, it is assumed that time slots are assigned to the nodes N1 to N4 as shown in FIG.

(2) Distance measurement of neighboring nodes When in a steady state, a node (for example, N1) transmits a position confirmation request signal on its own impulse signal. The position confirmation request signal is received by the other nodes N2 to N4 located within the solid line circle in FIG. Each of the nodes N2, N3, and N4 that has received the position confirmation request signal uses the data signal at the transmission timing of the data signal of its own node, and transmits a response signal to the position confirmation request signal to the request source. The content of the response signal is not particularly limited.

  The neighboring node position determination means 16 of the node N1 that has transmitted the position confirmation request signal checks whether or not a response (data) signal has been received for each time slot, and as shown in FIG. For the time slot, a time slot table in which a data signal including a response signal has been received (1) or not (0) is created and given to the on / off determination means 17 for holding.

  As will be described later, for a time slot in which a data signal including a response signal could be received, the power of the receiving unit of the data communication means 15 was turned on in that time slot, and the data signal including the response signal could not be received. For the time slot, the power supply of the receiving unit of the data communication means 15 is controlled to be turned off within the time slot.

(3) Reception of Data Signal When an impulse signal is transmitted from the own node N1, an impulse transmission completion notification is input to the on / off determination means 17. The on / off determination means 17 refers to the time slot table and checks whether or not the data signal having the node number 1 is received. Since the on / off determination unit 17 is “0”, the power of the receiving unit of the data communication unit 15 is turned off.

  From the impulse signal receiving unit 11, a reception notification of a subsequent impulse signal related to another node is input to the on / off determination unit 17. At this time, the on / off determination means 17 also refers to the time slot table and checks whether or not the data signal of the node number 2 has been received. In this case, since it is “1”, the power of the receiving unit of the data communication means 15 is turned on.

  Similarly, the impulse signals from the nodes N3 and N4 are received, and the power of the receiving unit is turned on / off according to whether or not the data signal is received in the time slot table.

  FIG. 5B shows the presence / absence of reception of the data signal in each time slot when the steady state is reached. In FIG. 2, data signals can be received in the time slots assigned to the nodes N2 and N4 located within the dotted circle, and at this time, the power of the receiving unit is turned on. In the time slot in which the node N3 transmits the data signal, the node N1 is in a state where the power of the receiving unit is turned off, but the node N1 receives the data signal from the node N3 as shown in FIG. There is no problem because it is located in a position where it cannot.

(A-3) Effect of First Embodiment According to the first embodiment, time slots can be allocated in an autonomous and distributed manner as each node interacts with neighboring nodes. In addition, for each other node to which the impulse signal arrives, it is determined whether the data signal from the other node can be received, and in the time slot assigned to the other node at a long distance where the data signal cannot be received, Since the power supply of the receiving unit is turned off, power saving can be achieved as compared with the case where the receiving unit is always turned on.

(B) Second Embodiment Next, a communication timing control device, a communication timing control method, a node, and a communication system according to a second embodiment of the present invention will be described with reference to the drawings.

  In the second embodiment, as in the first embodiment, since the power supply ON / OFF control function of the receiver is provided, a situation in which the power of the receiver is turned off during effective data reception is avoided. It was made in an attempt.

  In the case of the node arrangement shown in FIG. 2 described above, the node N1 exchanges impulse signals with the nodes N2, N3, and N4, and enters a steady state in phase relationship through interaction. On the other hand, when looking at the range where the impulse signal can be transmitted / received focusing on the node N2, the other nodes in the range are the nodes N1, N4 and N5, and the node N2 is an impulse with the nodes N1, N4 and N5. Signals are exchanged, and a steady state of phase relationship is established by interaction.

  As described above, since the node group with which the node N1 interacts is different from the node group with which the node N2 interacts, the time slot for the same node is viewed from the node N1, as shown in FIG. The time slot allocation width (time slot length) in this case may differ from the time slot allocation width as viewed from the node N2.

  The second embodiment is intended to avoid a situation in which the power of the receiving unit is turned off during effective data reception even in such a situation.

  FIG. 8 is a block diagram showing an internal configuration of a node according to the second embodiment, and the same reference numerals are assigned to the same and corresponding parts as those in FIG. 1 according to the first embodiment.

  The node of the second embodiment includes a time slot measuring unit 18 and a time slot length holding unit 19 in addition to the node configuration of the first embodiment.

  The time slot measuring means 18 has a function of measuring the time slot length of the time slot of its own node. The measured time slot length is given to the time slot length holding means 19 via the communication timing calculation means 12. The method of measuring the time slot length is arbitrary, but one method will be clarified in the description of the operation described later.

  The time slot length holding means 19 holds the time slot length of the own node and the time slot lengths of all other nodes that are in phase interaction with the own node.

  The communication system of the second embodiment includes (1) formation of a steady state by phase interaction between neighboring nodes, (2) measurement of the distance of neighboring nodes that interact with phase, and (3) time slot length of the own node. The procedure is as follows: measurement, (4) taking in the time slot length of a neighboring node, and (5) receiving a data signal. Since procedures (1) and (2) are the same as those in the first embodiment, the subsequent operations will be described.

(3) Measurement of time slot length of own node When a notification of transmission of an impulse signal from the own node is input to the time slot measuring means 18, the time slot measuring means 18 starts time measurement and receives a subsequent impulse signal. The time until the notification is input from the impulse signal receiving means 11 is measured. The time slot measurement unit 18 gives the measurement result to the time slot length holding unit 19 via the communication timing calculation unit 12 or directly, and causes the time slot length holding unit 19 to hold the measurement result.

(4) Taking in the time slot length of a neighboring node When a steady state is reached and the time slot of its own node is reached, the communication timing calculation unit 12 sets the time slot length of its own node held in the time slot length holding unit 19 Is transmitted using the data signal from the data communication means 15.

  On the other hand, when receiving the band request signal, the data communication unit 15 describes the time slot length included in the band request signal in the time slot length holding unit 19 as the time slot length related to the transmission source node of the band request signal. And hold it. If the time slot number of the own node is “1” and a bandwidth request signal is received in the subsequent time slot, the time slot length is written in the node number “2”. The data communication means 15 receives the time slot length again until it becomes the time slot of its own node, and creates a time slot length table as shown in FIG. 9 in the time slot length holding means 19. FIG. 9 shows an example of a table in the node N1.

  The node number in the table of time slot length is that the own node is “1” and other nodes that exchange impulse signals are described in the time slot allocation order. The time slot length of the own node is set to “0” on this table. The time slot length of the node (N3) that cannot receive the band request signal is also set to zero.

(5) Reception of data signal When an impulse signal subsequent to the own node is received, the time slot length table is referred to and the receiving unit is turned on for the time slot length 4 of the node N2, as shown in FIG. To. Since the time slot length is 4, when the impulse signal of the node N3 is received, the time slot length is not over and the receiving unit remains in the on state. In the on state, the time slot length holding means 19 is not referred to, and it waits for the time slot of the previous node to be turned off. In this case, when the time advances by 1 from the start of the time slot of the node N3, it is turned off. When the impulse signal of the node N4 is received, the time slot width 3 is turned on. The on / off control as described above is repeated only during the steady state to receive the data signal.

  Also in the second embodiment, the power saving can be expected by the on / off control of the power supply of the receiving unit similar to the first embodiment.

  Even if a data signal arrives beyond the time slot length seen from the own node, according to the second embodiment, the power of the receiving unit is not turned off during reception, and all can be received, in other words Even if the time slot length seen from the own node is different from that seen from the neighboring nodes, it is possible to prevent the reception of the data signal.

(C) Other Embodiments From the configuration of the second embodiment, the neighboring node position determination unit 16 may be omitted, and only the time slot measurement unit 18 and the time slot length holding unit 19 may function.

  The present invention can be applied not only when the communication path is a wireless communication path but also when the communication path is a wired communication path.

  In addition to the above, various modifications can be made to the present invention. For example, various modifications applicable to the present invention are described in Japanese Patent Application No. 2003-328530 and the drawings.

It is a functional block diagram which shows the internal structure of the node of 1st Embodiment. It is a block diagram which shows the example of arrangement | positioning of the node of the communication system of 1st Embodiment. It is explanatory drawing (1) of the tuning between nodes in the communication system of 1st Embodiment. It is explanatory drawing (2) of the tuning between nodes in the communication system of 1st Embodiment. It is explanatory drawing which shows the relationship between the time slot allocation example of 1st Embodiment, and reception of a data signal. It is explanatory drawing of the holding information of reception ON / OFF according to the time slot (node) of 1st Embodiment. It is a functional block diagram which shows the internal structure of the node of 2nd Embodiment. It is explanatory drawing which shows the relationship between the time slot width according to node of 2nd Embodiment, and the period of the incoming data signal. It is explanatory drawing of the holding | maintenance information of the reception ON period according to time slot (node) of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Impulse signal reception means, 12 ... Communication timing calculation means, 13 ... Impulse signal transmission means, 14 ... Tuning determination means, 15 ... Data communication means, 16 ... Neighborhood node position determination means, 17 ... On / off determination means, 18 ... time slot measuring means, 19 ... time slot length holding means.

Claims (5)

A communication timing control device provided in each of a plurality of nodes constituting a communication system,
With receive state variable signal indicating the operation timing of another node, a state variable signal communication means for transmitting a state variable signal indicating the operation timing of the own node intermittently,
Based on the state variable signal and the basic speed information of the transition from the other nodes that received the above state variable signal communication unit transitions the operation timing of the own node, the state variable signal from the local node that reflects this transition Timing determining means for generating and providing to the state variable signal communication means;
State variable signals of other nodes that received the above state variable signal communication unit, and, based on the operation timing of the node where the timing determination means has determined the relationship between operation timing of the own node and other nodes stable state Continuity determination means for determining whether or not
Data transmission means for transmitting a data signal for each periodic data transmission period determined by the operation timing of the own node when determined to be in a stable state;
A data receiving means for receiving a data signal from another node when the stable state is determined;
Even if the timing determination means is another node that transmits a state variable signal used for processing, the other node is classified according to whether or not the data signal from the other node reaches the node, and the data signal is And a reception on / off control means for turning off the power of the data reception means during at least a part of a data transmission period of another node that does not reach the communication timing control device. A self-node data transmission period notifying means for transmitting information on the data transmission period of the self-node to other nearby nodes;
The communication timing control device according to claim 1, wherein the reception on / off control means ensures the power-on state of the data reception means during a data transmission period notified from another node.   A node comprising the communication timing control device according to claim 1.   A communication system comprising a plurality of nodes according to claim 3. A communication timing control method executed by each of a plurality of nodes constituting a communication system,
With receive state variable signal indicating the operation timing of another node, a state variable signal communication step of transmitting intermittently the state variable signal indicating the operation timing of the own node,
Based on the state variable signal and the basic speed information of the transition from the other nodes that the state variable signal communication process has received, shifts the operating timing of the own node, the state variable signal from the local node that reflects this transition A timing determination step that generates and gives to the state variable signal communication step;
State variable signals of other nodes that received the state variable signal communication process, and, based on the operation timing of the node where the timing determination process is determined, relation between operation timing of the own node and other nodes stable state A continuity determination step of determining whether or not
A data transmission step of transmitting a data signal for each periodic data transmission period determined by the operation timing of the own node when determined to be in a stable state;
A data receiving step for receiving a data signal from another node when the stable state is determined;
Even if the timing determination step is another node that sends a state variable signal used for processing, the other node is classified according to whether or not the data signal from the other node reaches the node, and the data signal is And a reception on / off control step of turning off the power of the configuration in which the data reception step functions in at least a part of the data transmission period of the other node that does not reach the communication timing control method.

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