JP2006074611A - Transmission medium access control apparatus, method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of realizing the TDMA under an equally distributed environment and enhancing the substantial utilizing efficiency of various resources in nodes. <P>SOLUTION: A transmission medium access control apparatus includes: a state variable signal communication section; a timing determining section; a data transmission section; a data reception section; a path setting control signal processing section; a path setting section that sets reception timing designation information for designating an operating timing denoted by a state variable signal transmitted from a just preceding node in the case of receiving a path setting control signal from the just preceding node being a just preceding sender on the relaying path of the path setting control signal to carry out path setting; and a data reception operation control section that ordinarily deactivates the data reception section but activates the data reception section in the operating timing denoted by the reception timing designation information set to the path setting section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission medium access control apparatus, a transmission medium access control method, and a transmission medium access control program. For example, as in an ad hoc network, an equal distributed communication in which a node relays data transmitted from another node. It is suitable for application to a system or the like.

  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 method, when the number of nodes (number of channels) increases, the number of channels that can be simultaneously communicated decreases due to frequent collisions.

In the TDMA system, different time slots are assigned to each node, and each node transmits data in the time slot assigned to itself. The TDMA system is easier to increase the number of channels that can be simultaneously communicated than 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

  By the way, it is not always easy to realize TDMA in an equally distributed environment in which each node does not receive control from a special node such as the management node described above and operates autonomously.

  The time slot defines the transmission right of each node. However, when there is no data that needs to be transmitted, each node has the transmission right (the time slot is assigned). Even if it does not transmit valid data. However, whether or not each node has the data that needs to be transmitted is usually unpredictable to other nodes in the vicinity, so that the other nodes in the vicinity can always deal with data when it arrives. It is necessary to maintain a state of waiting for reception (waiting for reception).

  In the reception wait state, for example, storage resources are consumed by securing a storage area (buffer) for temporarily storing the received data on the main storage device, and the received data is the original data. However, even if it is noise, etc., the processing power is consumed to determine whether it is the original data, etc., and the power is consumed because the processing power functions. Resources are likely to be consumed. Therefore, if the reception waiting state becomes longer as in the prior art, it can be said that the substantial utilization efficiency of various resources in the node is low.

  In order to solve such a problem, the first aspect of the present invention executes access control for a transmission medium by allowing the own node to access the transmission medium using any of a plurality of periodically circulated time slots. A transmission medium access control device, (1) a state in which a state variable signal indicating an operation state or operation timing of another node is received and a state variable signal indicating an operation state or operation timing of the own node is intermittently transmitted A variable signal communication unit, and (2) based on a state variable signal received from another node received by the state variable signal communication unit, the operation state or operation timing of the own node is transited, and the own node reflecting this transition One state variable signal or a plurality of state variable signals in the vicinity where the state variable signal reaches A timing determination unit that recognizes a time slot in which another node can transmit a data signal; (3) a data transmission unit that periodically transmits a data signal for each time slot determined by the operation timing of the own node; and (4) A data receiving unit for receiving a data signal from another node; and (5) generating a path setting control signal including initial transmission source information indicating at least a node that is an initial transmission source (for example, a source node). Or a route setting control signal processing unit to be relayed, and (6) a route setting control signal is received from the immediately preceding node that is the previous transmission source on the relay route of the route setting control signal, and the route setting is performed. A path setting unit that sets reception timing designation information that designates an operation timing indicated by the state variable signal transmitted by the immediately preceding node; and (7) normally, the data reception A data reception operation control unit that operates the data reception unit at the operation timing indicated by the reception timing designation information set in the path setting unit without operating the unit.

  According to a second aspect of the present invention, there is provided a transmission medium access control method for performing access control on a transmission medium by allowing the own node to access the transmission medium using any one of a plurality of periodically circulated time slots. (1) The state variable signal communication unit receives the state variable signal indicating the operation state or operation timing of the other node, and intermittently transmits the state variable signal indicating the operation state or operation timing of the own node. (2) Based on the state variable signal received from the other node received by the state variable signal communication unit, the timing determination unit transitions the operation state or operation timing of the own node, and from the own node reflecting this transition One state variable signal or a plurality of state variable signals in the vicinity where the state variable signal reaches The other node recognizes a time slot in which the data signal can be transmitted, (3) the data transmitting unit periodically transmits the data signal for each time slot determined by the operation timing of the own node, and (4) the data receiving unit Receives a data signal from another node, and (5) the path setting control signal processing unit generates or relays a path setting control signal including initial transmission source information indicating at least a node that is the initial transmission source. (6) When the route setting unit receives the route setting control signal from the immediately preceding node that is the immediately previous transmission source on the relay route of the route setting control signal and performs route setting, The reception timing specification information for specifying the operation timing indicated by the transmitted state variable signal is set. (7) The data reception operation control unit normally does not operate the data reception unit, and sets the route. Reception timing specification information set in the in the operation timing shown, wherein the operating the data reception unit.

  Further, according to the third aspect of the present invention, there is provided a transmission medium access control program for performing access control on a transmission medium by causing the own node to access the transmission medium using any one of a plurality of periodically circulated time slots. And (1) a state variable signal communication that receives a state variable signal indicating an operation state or operation timing of another node and intermittently transmits a state variable signal indicating the operation state or operation timing of the own node. (2) Based on the state variable signal received from the other node received by the state variable signal communication function, the operation state or operation timing of the own node is transitioned, and the state variable from the own node reflecting this transition A signal is generated and given to the state variable signal communication function. Or a timing determination function for recognizing a time slot in which a plurality of other nodes can transmit a data signal, and (3) a data transmission function for periodically transmitting a data signal for each time slot determined by the operation timing of the own node; (4) A data receiving function for receiving a data signal from another node, and (5) a path setting for generating or relaying a path setting control signal including initial transmission source information indicating at least a node that is an initial transmission source. (6) When a route setting control signal is received from the immediately preceding node that is the immediately preceding transmission source on the relay route of the route setting control signal and the route setting is performed, the immediately preceding node transmits A path setting function for setting reception timing specification information for specifying the operation timing indicated by the state variable signal, and (7) normally operating the data reception function. Not, the operation timing reception timing specifying information set in the route setting function is shown, wherein the was realized and the data receiving operation control function for operating the data reception function.

  According to the present invention, TDMA can be realized in an equally distributed environment, and substantial utilization efficiency of various resources in a node can be increased.

(A) Embodiments Embodiments of a transmission medium access control apparatus, a transmission medium access control method, and a transmission medium access control program according to the present invention will be described below.

  This embodiment proposes a new communication protocol. This communication protocol is a kind of TDMA.

(A-1) Configuration of the First Embodiment FIG. 2 shows an overall configuration example of the communication system 10 according to the present embodiment.

  In FIG. 2, the communication system 10 includes nodes A to G.

  Each node has a transmission function for transmitting impulse signals and data signals, a reception function for receiving impulse signals and data signals transmitted from other nodes, a relay function for transmitting data signals transmitted from other nodes to other nodes, etc. Have the same function. The impulse signal is a control signal (timing signal) used when each node transmits the phase position of its own time slot to other nodes. The data signal is user data used in a predetermined communication application. The communication application includes a general program such as an electronic mail and a route control program. Therefore, in this embodiment, it is assumed that the control signals (route setting request signal and response signal) transmitted and received by the route control program for route control are also data signals. In this embodiment, this path control is important.

  Each of the nodes A to G can constitute an ad hoc network.

  The time slot is for restricting the transmission right of each node, and the reception right is basically held by all nodes, but in this embodiment, each node has its own reception right. It is characterized by providing a period during which no use is made.

  In addition, since there is a physical limit (cover area) in the range in which the radio signal such as the impulse signal and the data signal reaches, each node has only the impulse signal and data in other nodes existing within its own cover area. A signal can be delivered. As will be described later, it is desirable that the coverage area of the impulse signal is larger than the coverage area of the data signal.

  Each of the nodes A to G may have mobility such as a notebook personal computer, but may not have mobility.

  In FIG. 2, the nodes E and F receive the data signal RG1 transmitted by the node G, the node A receives the data signal RF1 transmitted by the node F, and the data signals RA1 transmitted by the node A are represented by the nodes B to D. Node A receives the data signal RE1 transmitted by the node E, the node C receives the data signal RD1 transmitted by the node D, and the node C receives the data signal RB1 transmitted by the node B. ing.

  Here, mainly, these data signals RG1, RF1, RA1, RE1, RB1, and RD1 are assumed to be the path setting request signals. The route setting request signal is used for requesting setting of a route for the initial transmission source node, which is the original transmission source, to communicate a data signal (for example, a data signal (user data) constituting the content of the e-mail). This is a control signal to be used. Since it is impossible for the initial transmission source node to predict what kind of route can be set, the route setting process includes route search processing. Although various methods can be used as a route search method, flooding is used here.

  Note that the route setting request signals RG1, RF1, RA1, RE1, RB1, and RD1 are externally different signals in that the nodes to be transmitted and received are different, but are transmitted because the node G requests route setting. The signals are almost the same in terms of content in that they are signals or signals derived from the signals. Therefore, when it is not necessary to distinguish between them, RG1, RF1, RA1, RE1, RB1, and RD1 are simply referred to as a “route setting request signal”.

  Although all nodes in the communication system 10 can be the initial transmission source node of the route setting request signal, in the example of FIG. 2, the initial transmission source node of the route setting request signal is G. The route setting request signals RG1, RF1, RA1, RE1, RB1, and RD1 are one route setting request signal RG1 when the node G first transmits, but in the process of being relayed by different nodes, RG1 RF1, RA1, RE1, RB1, RD1, etc.

  In the example of FIG. 2, since the nodes A to F belong to the coverage area of the impulse signal and the data signal, the impulse signal and the data signal can be exchanged. Similarly, since the nodes G, E, and F belong to the coverage area of the impulse signal and the data signal, the impulse signal and the data signal can be exchanged. However, since the node G and the nodes A, B, C, and D do not belong to each other within the cover area, the impulse signal and the data signal cannot be directly exchanged.

  In order to simplify the description, the nodes other than the nodes A to G are not basically referred to, but actually, between the nodes A to G shown in FIG. 2 and the nodes not shown in FIG. Of course, data signal communication and impulse communication may be performed.

  In the following description, FIG. 8 is used as necessary. Each node N1 to N16 in FIG. 8 is a node having the same function as the node A or the like.

  In FIG. 8, solid circles centered on the nodes of interest N1 and N2 indicate the range in which the nodes N1 and N2 can receive the impulse signals transmitted from other nodes (impulse signal cover area). In the example of FIG. 8, the target node N1 can receive the impulse signals transmitted from the nodes N2, N3, and N9, and the target node N2 can receive the impulse signals transmitted from the nodes N1, N3 to N12.

  A dotted circle centered on the target nodes N1 and N2 in a range narrower than the solid circle indicates a range (data signal cover area) in which the other nodes and the target nodes N1 and N2 can exchange data signals. In the example of FIG. 8, the node of interest N1 can exchange data signals only with the node N3, and the node of interest N2 can exchange data signals with the nodes N3, N7, N8.

  In this embodiment, as shown in FIG. 8, even if there is a bias in the arrangement of nodes, the time slots in each node can be allocated as evenly as possible (including the case of reassignment).

  The internal configuration of the node A is, for example, as shown in FIG. The internal configurations of the other nodes B to G and nodes N1 to N16 are the same.

(A-1-1) Internal Configuration Example of Node In FIG. 1, the node A includes an impulse signal reception unit 11, a communication timing calculation unit 12, an impulse signal transmission unit 13, a tuning determination unit 14, and a data signal. Communication means 15, time slot width measurement means 16, angular velocity change means 17, route setting means 18, and route information storage means 19 are provided.

  Among these, the impulse signal receiving means 11 receives an impulse signal (not including destination information) transmitted by a nearby node (for example, another node existing in the coverage area of the impulse signal related to the own node A). It is. The impulse signal has, for example, an impulse shape such as a Gaussian distribution shape. The impulse signal receiving unit 11 gives the received impulse signal itself, a waveform-shaped signal thereof, or an impulse signal regenerated based on the received impulse signal to the communication timing calculation unit 12 and the tuning determination unit 14.

  The communication timing calculation unit 12 forms and outputs a phase signal that defines the communication timing at the node A based on a signal (and a route information table TB1 described later) given from the impulse signal reception unit 11. .

Here, assuming that the node A is a node i in order to generalize the node A and the phase value of the phase signal at time t is θi (t), the communication timing calculation means 12 can change the amount of change shown in the equation (1). The phase signal θi (t) is changed step by step. 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, for example, 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 k, and the function R (θi (t), σ (t)) This is a phase response function that expresses a response characteristic that changes its basic rhythm in response to the reception of an impulse signal from, for example, according to equation (2).

  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 neighboring 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. 9 and 10 show the relationship formed between a target node (own node) i and a neighboring node (other node) j, that is, each nonlinear vibration rhythm when attention is paid to a certain node i. The phase relationship between them changes with time.

  FIG. 9 shows a case where there is one neighboring node j for the node of interest i. In FIG. 9, 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 as shown in FIG. 9A, the phases of the two mass points are close to each other in the initial state. However, with the passage of time, the state (transient state) shown in FIG. 9B is changed to a steady state in which the phase difference between the two mass points is almost π as shown in FIG. 9C.

  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 (phase interaction) based on the transmission / reception of an impulse signal occurs between nodes, these mass points change their angular velocities (slow and steep), and as a result, a steady state that maintains an appropriate phase relationship To reach. 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. 10 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 3 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.

  9 and 10 show the case where there are one or two other nodes that transmit and receive the impulse signal in the vicinity of the target node. However, as illustrated in FIG. 2 and FIG. The arrangement relationship of the nodes is more complicated than those assumed in FIG. 9 and FIG.

  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 signal communication unit 15, and the time slot width measurement unit 16.

  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. 9, 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 the 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. 9B and 10B) or It is determined which state is “steady state” (see FIG. 9C or FIG. 10C). The tuning determination means 14 observes the reception timing of the impulse signal (corresponding to the output timing of the other node) and the transmission timing of the impulse signal from its own node, and the time difference between the transmission timings of a plurality of nodes that exchange the impulse signal Is determined to be in a “steady state” when it is stable over time. 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 observed value β of the phase signal θi (t), the difference (phase difference) between adjacent values 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) in the phase difference Δ in the successive periods 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-described 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 signal communication means 15.

  The data signal communication unit 15 includes a data signal transmission unit 15A and a data signal reception unit 15B. The data signal transmitting unit 15A transmits the data signal, and the data signal receiving unit 15B receives the data signal. By providing these means 15A and 15B, the data signal communication means 15 transmits data (data signal) as an original transmission source, or receives data as a final destination. And can transmit and receive data relayed by itself.

  The data signal communication means 15 performs data transmission (data signal transmission) in a fixed manner assigned by a time slot (system (corresponding to the management node) described later) when the tuning determination signal indicates “steady state”. The transmission operation is stopped when the tuning determination signal indicates “transient state”.

  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. 9C, 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. If 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 and the data signal or the like does not collide. 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, for example, 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.

  In order to review the assigned time slot by the functions of the impulse signal receiving means 11, the communication timing calculation means 12, the impulse signal transmission means 13, the tuning determination means 14 and the data signal communication means 15 described above (the width of the time slot is as small as possible). For equality), time slot width measuring means 16 and angular velocity changing means 17 are provided. The time slot width measuring unit 16 and the angular velocity changing unit 17 may function when a review activation switch (not shown) is operated, or may always function without waiting for an external operation. .

  The time slot width measuring means 16 measures the reception interval of the impulse signal received by the node. The time slot width measuring means 16 measures the number of received impulses in one cycle (the transmission interval of the impulse signal of the own node), and examines the number of nodes that can transmit / receive the impulse signal to / from the own node. Further, the time slot width measuring means 16 determines whether or not to perform control to increase the assigned time slot width from the time slot width and period assigned to the own node.

  The angular velocity changing means 17 transmits the impulse signal by requesting the communication timing calculating means 12 to change the phase when it is determined that the time slot width measuring means 16 performs control to widen the assigned time slot width. Responsible for shifting the timing.

The functions of the time slot width measuring unit 16 and the angular velocity changing unit 17 will be described in more detail with reference to FIGS.
FIGS. 11A and 11B show the time slot assignment of each node viewed from the nodes N1 and N2 in the case of the node arrangement as shown in FIG. When viewed from the node N1, there are 4 nodes (including the node N1) within the radius R (the radius of the solid circle), and when viewed from the node N2, there are 12 nodes (including the node N2), each of which is one cycle. Are divided into four (FIG. 11A) or 12 (FIG. 11B), and time slots are allocated.

  In FIG. 11, the time slots assigned with “N1” to “N12” represent time slots assigned to the node N12 from the node N1 in FIG. Although nodes N1, N2, N3 and N9 are similar nodes, they are affected by the phase interaction of neighboring nodes, and as shown in FIG. have. In order to correct such an imbalance of allocation as much as possible (in order to review the assigned time slot), the time slot width measuring means 16 and the angular velocity changing means 17 are provided, and the time slots are reassigned. .

  The time slot reassignment operation is performed in two stages: (S1) determination of necessity for expanding the time slot width and (S2) phase shift control.

(S1) Determination of necessity of time slot width expansion The time slot width measuring means 16 of each node counts the number of received impulse signals in one cycle from the transmission of the self impulse signal to the next transmission of the self impulse signal. The number of nodes in the impulse signal receivable range (in the impulse signal cover area) is examined. For example, the time slot width measuring unit 16 of the node N1 receives a single impulse signal from the transmission of the self impulse signal at the timing <1> in FIG. 11A until the next transmission of the self impulse signal. Count the number of signals and check the number of nodes in the coverage area of the impulse signal. Thereby, the time slot width measuring means 16 of the node N1 obtains the number of nodes “4”. Further, the time slot width measuring means 16 of each node measures the time from when the impulse signal is transmitted until the impulse signal is received from another node. As a result, the time slot width measuring means 16 of the node N1 makes the time between <1> and <2>, the time between <1> and <3>, <1> and <9 in FIG. By measuring the time between> and arranging these measurement times, the allocated time of each time slot can be obtained.

  When one period is measured as described above, the angular velocity changing unit 17 determines whether or not the time slot allocation width of the own node is smaller than when the time slot allocation width is allocated equally. For example, if the value “2π / number of nodes−time slot width of own node” (here, a difference but may be a ratio) is equal to or smaller than a predetermined threshold value, phase shift control is performed. judge. In the case of the example of FIG. 11A, since the time slot width of the node N1 is smaller than the case where the time slots are evenly allocated, it is determined by the angular velocity changing means 17 that the phase shift control is performed.

  Note that the criterion for determining whether or not to perform phase shift control is not limited to this. For example, phase shift control may be performed if the following conditions (PA) and conditions (PB) are satisfied, and phase shift control is performed when a plurality of conditions are satisfied. Also good.

Condition (PA): Time slot width allocated to own node <maximum time slot width / 2
Condition (PB): Sum of time slots before and after own impulse signal <maximum time slot width (S2) Phase shift control When angular velocity changing means 17 receives an impulse signal defining the end of the time slot of its own node (FIG. 11 (A) <2>) phase θi (t) and the phase difference from phase θi (t + 1) at the time of receiving the next impulse signal (<3> in FIG. 11A). And the phase difference θi (t + 1) −θi (t) is held. Further, the angular velocity changing means 17 checks the phase difference θi (t + 2) −θi (t + 1) at the time of receiving the next impulse signal (<9> in FIG. 11A), and if this phase difference is large, the impulse is changed. The signal phase θi (t + 1) and phase difference θi (t + 2) −θi (t + 1) are held. Such an operation is repeated until the self impulse signal is transmitted again. Then, the transmission phase of the impulse signal of the own node is changed to the position of the held phase + (1/2 of the phase difference). From the viewpoint of the node N1, the time slot assigned to the node N3 is the largest (as seen from the held phase difference), so the phase of the node N1 is shifted to this position as shown in FIG. The transmission of the impulse signal is started.

  FIGS. 11C and 11D show the time slot widths as viewed from each of the node N1 and the node N2 when the phase shift control is performed. The node N1 has a smaller time slot width due to the influence of the preceding and following nodes, but the allocated width increases. At this time, the state shown in FIG. 12A transitions from the state shown in FIG. 12A to the state shown in FIG.

  The phase shift destination is not limited to the phase within the range of the maximum time slot, but may be other than this. For example, you may make it move to the position where a continuous time slot (next time slot) is the largest.

  Actually, as in this example, it is often difficult to assign time slots to each node completely evenly (assigning a time slot of the same time width to each node) depending on the arrangement situation of the nodes, In the following, for simplicity of explanation, it is assumed that time slots having an equal time width are basically allocated to each node in a steady state.

  The route setting means 18 performs route setting based on the route setting request signal or the response signal received from the other node by transmitting the route setting request signal with the node A as the original transmission source. Therefore, the function of the above-described route control program mainly corresponds to the route setting means 18. When performing route setting based on the route setting request signal or response signal received from another node, the route setting is performed, for example, by storing a route information table TB1 as shown in FIG. Executed by.

  The path information table TB1 in FIG. 4 includes an initial transmission source and reception timing as data items.

  Here, the initial transmission source registers the address of the initial transmission source node that is the initial transmission source of the route setting request signal or the response signal, and the reception timing is determined by the node A as its own node. A value indicating the number of the time slot of another node in the vicinity that has received the response signal directly from the time slot ATS of the node A is registered.

  Here, one cycle of time slots (ATS to FTS) assigned to 6 nodes A to F in the vicinity that can exchange data signals with each other is as shown in FIG. 7A as an example, and A → B → C It is assumed that it is circulating in order of →… → F. FIG. 3 shows the time slots shown in FIG.

  The time slot ATS is a time slot of the node A. During the time slot ATS, the node A has the transmission right of the impulse signal and the data signal.

  Similarly, the time slot BTS is the time slot of the node B. During the time slot BTS, the node B has the right to transmit the impulse signal and the data signal, the time slot CTS is the time slot of the node C, and the time slot CTS During the period, the node C has the right to transmit the impulse signal and the data signal, the time slot DTS is the time slot of the node D, and during the period of the time slot DTS, the node D has the right to transmit the impulse signal and the data signal. The slot ETS is a time slot of the node E. During the time slot ETS, the node E has the transmission right of the impulse signal and the data signal. The time slot FTS is the time slot of the node F, and during the time slot FTS, the node F is the impulse signal and data It has the right to transmit the signal.

  Even when a route setting request signal or a response signal, which is a data signal for route setting, is transmitted, each node cannot perform transmission until its own time slot arrives.

  As described above, the time slot is for limiting the transmission right of each node, and the reception right is basically held by all the nodes at all times. However, according to the route setting, the data signal receiving unit 15B is not operated (set to the non-operating state) within an unnecessary time slot period in which no route is set.

  On the other hand, one cycle of time slots (GTS to FTS) assigned to three neighboring nodes G to F that can exchange data signals with each other may be as shown in FIG. 7B as an example. In FIG. 7B, circulation is performed in the order of G → F → E.

  In FIG. 7B, the time slot GTS is the time slot of the node G, and during the time slot GTS, the node G has the transmission right of the impulse signal and the data signal, and the time slot ETS is the time slot of the node E. During the time slot ETS, the node E has the transmission right of the impulse signal and the data signal, the time slot FTS is the time slot of the node F, and during the time slot FTS, the node F has the transmission right of the impulse signal and the data signal. have.

  The route information table TB1 shown in FIG. 4 includes two rows L1 and L2. The row L1 corresponds to the route setting request signal received by the node A, and the row L2 This corresponds to the response signal received by the node A. Here, the row indicates a horizontal arrangement excluding data items in the route information table TB1.

  Since the initial transmission source node of the route setting request signal is G, the direct transmission source is the node F, and the time slot FTS of the node F is the fifth as viewed from the ATS as shown in FIG. “5” is registered as the reception timing of the row L1.

  As for the response signal, the initial transmission source node and the direct transmission source are the same node C, and the time slot CTS of the node C is the second as viewed from the ATS as shown in FIG. “2” is registered as the timing.

  If registered in this way, the communication timing calculation means 12 corresponds to the second time slot CTS from the ATS and the fifth time slot FTS from the ATS in one cycle shown in FIG. Control can be executed such that the data signal receiving means 15B is in an operating state (a reception waiting state) only during a period, and in a non-operating state during other periods. The reception waiting state is a state belonging to the operation state of the data signal receiving means 15B, and is a state waiting for arrival so that a data signal that cannot be predicted when it can be received can be dealt with whenever it arrives. is there. Except for the case where the utilization rate of time slots per unit time is extremely high, it is considered that most of the operating state of the data signal receiving unit 15B is in a reception waiting state.

  The operation of the present embodiment having the above configuration will be described below.

(A-2) Operation of First Embodiment Assuming that no route is set in the communication system 10, a node having user data to be transmitted performs route setting before transmitting the user data. Is required. Here, it is assumed that the node G is such a node. Note that the fact that no path is set means that the data signal receiving means 15B is in an operating state over the entire period of one cycle in all the nodes A to G. Therefore, when there is no valid data signal to be received at that time, the data signal receiving unit 15B in each of the nodes A to G maintains the above-described reception waiting state.

  In FIG. 2, since only the nodes E and F are located in the data signal cover area of the node G, when the node G transmits the route setting request signal RG1, the route setting request signal RG1 is Received by E and F.

  The route setting request signal RG1 is transmitted in the GTS of FIG. 7B, which is the time slot of the node G, but the node G keeps the data signal receiving means 15B in the non-operating state within the time slot GTS. Can be. Within the period of its own time slot GTS, the other nodes E and F located in the cover area cannot transmit the data signal, and the other nodes E and F and the own node G have the same transmission power and the same. If it is assumed that a frequency data signal is transmitted, it is difficult for the radio node to effectively receive a data signal transmitted from another node arriving from a remote location, and there is no practical benefit even in a reception waiting state. Because.

  Although the route setting request signal RG1 may include various information, it is assumed that at least the address GAD1 of G that is the initial transmission source node is included. The route setting request signal RG1 may include the address of a node (final destination node) that is the final destination of the route setting request signal. The expiration date information may be included together with the address of the final destination node or instead of the address of the final destination node. The expiration date information is information that specifies an upper limit value such as the number of hops and time that the route setting request signal derived from RG1 is relayed in the communication system 10, and the route setting request signal is transmitted to a node that does not need to be relayed. It can be used to prevent relaying or unnecessary increase in communication traffic.

  Here, the address of the node (for example, G) is identification information that can uniquely identify each node in at least the communication system 10.

  The route setting request signal RG1 does not need to include the addresses of the nodes E and F to be received directly, but is unspecified when it is essential to describe the addresses according to the specifications of the communication protocol. A broadcast address that designates a number of nodes as destinations may be described. Of course, if the addresses of neighboring nodes can be recognized by the respective nodes A to G in the communication system 10 at that time, the address is individually designated and a route setting request signal is transmitted to the next node. However, here, it is assumed that the address of the neighboring node is not recognized and broadcasts. If the address of the source node (here, G) is described in the broadcast route setting request signal, the node (here, E or F) that has received the route setting request signal broadcasts from the description. Since the address of the node (for example, G) can be recognized, unicast can be performed when the response signal is transmitted.

  The route setting request signal RG1 transmitted by the node G is received almost simultaneously by the data signal receiving means 15B of the nodes E and F. The data signal receiving means 15B in the reception waiting state temporarily stores the received path setting request signal RG1 in the buffer already secured on the main storage device (not shown), The route is set by adding a row corresponding to the row L1 to the route information table TB1. This is a route setting for relaying in the forward direction in which the data signal (user data) transmitted by the node G that is the initial transmission source node is relayed.

  As apparent from FIG. 7B, when viewed from the node F, since the time slot GTS of the node G is second, “2” is registered as the reception timing of the route information table in the node F. Similarly, when viewed from the node E, since the time slot GTS of the node G is the first, “1” is registered as the reception timing of the route information table in the node E.

  In relaying the route setting request signal at each node (here, E and F), basically, the received signal may be transmitted as it is. In this case, the contents of the route setting request signal RG1 received by each node (for example, F) and the transmitted route setting request signal RF1 are the same. However, when the expiration date information is included in the route setting request signal, a process of decrementing (or subtracting) the value may be performed at the time of relaying.

  The two nodes E and F each transmit a route setting request signal stored in the buffer in their own node for relaying.

  However, as is clear from FIG. 7B, the time slot immediately after the GTS is the FTS, and the next is the ETS, so that the node F transmits first. Node E transmits when its own time slot ETS arrives after node F transmits.

  Although the node A belongs to both the cover area of the node F and the cover area of the node E, the node A first receives RF1 which is a path setting request signal transmitted by the node F for relaying. . At this time, the path setting in the forward direction is performed in the node A similar to that performed in the nodes F and E when the RG1 is received. With this route setting, the above-described row L1 is registered in the route information table TB1.

  As shown in FIG. 7A, since the time slot FTS of the node F is immediately before the time slot ATS of the own node when viewed from the node A, the path setting request signal is received immediately after receiving the path setting request signal RF1. RA1 is transmitted from node A.

  Note that after RF1 transmitted from the node F, RE2 transmitted from the node E arrives at the node A, but this RE2 is deleted (destroyed) on the buffer in the node A and is subject to relaying. Must not. Not only the node A but all nodes in the communication system 10 send the same route setting request signal (for example, a route setting request signal having the same initial transmission source node) within a predetermined time (for example, during one cycle). When received from a different node, only the route setting request signal received first is used for route setting, and other route setting request signals received thereafter are deleted in this way. Of course, the deleted route setting request signal is not subject to route setting or relay in the node A.

  As a result, the storage capacity (buffer capacity) and processing capacity can be saved inside each node. In addition, it is possible to prevent an infinite loop from occurring between nodes and suppress an increase in communication traffic. In addition, by selecting a route to be described later, a route having a short delay time for relaying that occurs when each node waits for the arrival of its own time slot is selected. This is also advantageous for improving the real-time property regarding communication.

  When any of the path setting request signals is discarded within the node (here, A), the node (here, E) that is the direct transmission source may be notified of the discard. . If it is known that the transmitted route setting request signal is discarded, it can be recognized that the own node (here, E) has deviated from the currently set route, so that the node (here, E) This is because it is possible to lengthen the time during which the data signal receiving unit 15B is in the non-operating state by canceling the route setting previously performed for the forward direction. Alternatively, each node may perform the cancellation when the response signal corresponding to the current route setting cannot be received within a predetermined time (for example, five cycles).

  The path setting request signal RA1 transmitted (broadcast) from the node A that has received the path setting request signal RF1 can be physically received by the nodes B to F existing in the cover area of the node A. The node E, F or the like that has already received the same route setting request signal is deleted (in FIG. 2, the route setting request signal RA1 reaching from the node A to the nodes E, F is not shown). Absent).

  Note that the time slot GTS of the node G does not exist in one cycle of the time slot of FIG. 7A, but the time slot GTS of the node G shown in FIG. 7B is a time slot of the node F. Since it is immediately before the FTS and immediately after the ETS which is the time slot of the node E, it corresponds to the phase position between the ETS and the FTS even in one cycle of FIG. Therefore, as apparent from FIG. 7A, since the route setting request signal RA1 received from the node A arrives at the earliest time for the nodes B to D, the route setting request signal (for example, the node E received after that) , RE1, etc. that arrive at the node D) will be deleted.

  In this way, a route in the forward direction is set in each node.

  Assuming that the initial transmission source node G designates C as the final destination node of the route setting request signal, this route setting request signal requests the setting of one route between the nodes G and C. . When each node executes the above-described cancellation, only one of the plurality of possible paths remains selected, and various resources in the nodes outside the path can be saved. In the case of the present embodiment, assuming FIG. 2, FIG. 7A and FIG. 7B, the remaining route is a route of G → F → A → C.

  Next, processing of the response signal will be described.

  The response signal is a control signal for route setting used for confirming the completion of the route setting in the forward direction and for setting the route in the backward direction. Therefore, as long as these two objectives can be achieved, there are various methods for the specification (included information) of the response signal itself and when each node transmits the response signal. For example, the following first to third methods can also be used. However, these are naturally limited by the information included in the route setting request signal.

  For example, in the first method, a node that has received a route setting request signal (not discarded) sends a route setting request signal to itself (for example, node F when viewed from node A). The node transmits a reply signal, and each node relays the reply signal to the node G, which is the original transmission source node, by relaying the reply signal in the reverse direction on the same path as the forward path. In this case, since the response signal is transmitted from all the nodes that have received the route setting request signal, the processing capacity of each node is consumed for relaying the response signal and the communication traffic increases. A route having a tree structure as a root can be set, and the route setting request signal does not need to include the address of the final destination node. Further, if the address of a node (for example, C) that is the initial transmission source of the response signal is described, each node (for example, A or G) that has received the response signal can determine from the description of the response signal, All nodes that can communicate with each other can be specified.

  In the second method, on the assumption that the expiration date information is included in the route setting request signal, the expiration date information is a predetermined value (for example, 0) in the process (subtraction of the expiration date information, etc.) in the own node. ), The node transmits a response signal. In this case, the processing capacity consumed for relaying the response signal and the necessary communication traffic are not as large as the first method, and it is not necessary to include the address of the final destination node in the route setting request signal. In addition, if each node adds its own address to the response signal at the time of relaying, the initial transmission source node G that finally receives the response signal recognizes the addresses of all the nodes on the route. The initial transmission source node G can exchange user data with an arbitrary node on the route.

  In the third method, assuming that the address of the final destination node is included in the route setting request signal, only the final destination node transmits a response signal. For example, when the address of the final destination node is an address that designates the node C, only the node C transmits a response signal, and the forward route and the return route are set between the nodes G, F, A, and C. Become. Of course, the final destination node is not necessarily one. As in the second method, if each node adds its own address to the response signal at the time of relaying, the initial transmission source node G can exchange user data with an arbitrary node on the route. You can also.

  In the first method and the third method, it is generally necessary to include expiration date information in the route setting request signal in order to suppress an increase in communication traffic of the route setting request signal. Probability is high. Also in the second method and the third method, it is possible to set a tree-structured route with the initial transmission source node G as a root.

  Regardless of which one of the first to third methods is used for route setting in the return direction, here, the route setting for the forward route is made between the nodes G, F, A, and C along with the relay of the route setting request signal. Next, it is assumed that the return route is set along with the relay of the response signal. The return path follows the same path as the forward path in the reverse direction.

  When the response signal is transmitted by the above-described unicast, in addition to the address of the node G as the final destination, the address of a nearby node as the direct destination is described in the response signal. For example, when the node C transmits a response signal, the address of the node A as a direct destination is described in the response signal together with the address of the node G as a final destination. In this case, the reply signal transmitted by the node C physically reaches the neighboring nodes B, D, etc., but the reception process of the reply signal is not performed in these nodes which are not designated as the destination, and designated as the destination. The response signal is received only at the node A. Here, it is assumed that the address CAD1 of the node C that is the initial transmission source node is described in the response signal.

  In the case of the present embodiment, each node needs to maintain the reception waiting state of the data signal receiving unit 15B for the entire period of one cycle only by setting the route in the forward direction. This is because it is impossible to predict in which time slot the response signal is transmitted. Therefore, at this time, the node A also maintains the data signal receiving means 15B in the operating state (reception waiting state) over the entire period of one period of the time slot, and can receive the reply signal transmitted by the node C.

  When the node A receives the response signal in the time slot CTS (that is, the period between the second impulse signal and the third impulse signal counted from the impulse signal transmitted from the node A), the node A returns. It can be recognized that the time slot CTS is used in the direction route setting. In addition, if the response signal describes the address CAD1 of the node C that is the initial transmission source node, the CAD1 can be recognized. Based on this recognition, in node A, row L2 of the route information table TB1 shown in FIG. 4 is registered.

  By the same operation as this, the route setting in the backward direction is also performed in the nodes F and G.

  Further, when the forward route and the return route are set between the nodes G, F, A, and C, the node G is mounted only during the period of the time slot FTS of FIG. The data signal receiving unit 15B is set in the operation state (waiting for reception), and the data signal receiving unit 15B is set in a non-operating state during other periods (GTS and ETS).

  The same processing is performed on the other nodes F, A, and C on the route. For example, in the node A, the data signal receiving means 15B mounted on the node A is operated only during the time slots FTS and CTS shown in FIG. 7A, and the other periods (ATS, BTS, DTS, ETS) Then, the data signal receiving means 15B is brought into a non-operating state.

  There are various specific methods for realizing such an operation in the node A or the like. For example, the node A transmits an impulse signal (the timing at which this transmission is performed is shown in FIG. 7A). The phase position of “A” in FIG. 2), the number of impulse signals transmitted by other nearby nodes is counted, and the count result is compared with the value of the reception timing in the path information table TB 1. At this time, such an operation can be realized by putting the data signal receiving means 15B in the reception waiting state for one time slot (for example, corresponding to the time until the next impulse signal can be received).

  If the contents of the path information table TB1 are as shown in FIG. 4, the node A itself has received the second impulse signal (which is transmitted by the node C) after the node A itself has transmitted the impulse signal. The data signal receiving means 15B is shifted from the previous non-operating state to the reception waiting state, and the data signal receiving means 15B is turned off at the timing when the third impulse signal (which is transmitted by the node D) can be received. Returning to the operating state, the non-operating state is maintained at the timing when the fourth impulse signal can be received, and the reception waiting state is entered at the timing when the fifth impulse signal (which is transmitted by the node F) can be received. Transition. Thereafter, at the timing when the node A transmits the impulse signal again, the node A is returned to the non-operating state, and the process of one cycle in FIG. Thereafter, the same process is repeated as long as the steady state is maintained.

  During this one cycle, the non-operating data signal receiving means 15B can, for example, allow a weak current to flow with emphasis on the speed of transition to the operating state. When the power supply to the signal receiving means 15B is completely cut off (turned off) and the power supply is resumed (turned on) to the operating state (waiting for reception), the power supply to the data signal receiving means 15B is supplied only in the CTS and FTS. The time chart of node A to be performed is as shown in FIG.

  When a data signal is actually received in the reception waiting state during one cycle, it is natural that the data signal receiving means 15B of each node executes the reception process.

  Compared with the necessity of maintaining the operation state (reception waiting state) of the data signal receiving means 15B over the entire period of one cycle in the conventional node, in this embodiment, the period of the reception waiting state is shortened. Conventionally, various resources (storage capacity, processing capability, power, etc.) of each node can be saved.

(A-3) Effect of the First Embodiment According to the present embodiment, TDMA can be realized in a peer-distributed environment, and the substantial utilization efficiency of various resources in the node (for example, A) is increased.

(B) Second Embodiment Hereinafter, only differences between the present embodiment and the first embodiment will be described.

  If the method of the first embodiment is strictly applied as it is, a node (for example, A) existing on the set path cannot receive any data signal from a node (for example, E) that does not exist on the path. A route setting request signal which is a kind of data signal cannot be received, and a new route including a node existing on the route cannot be set from a node not existing on the route. As a method for solving this problem, the method used in this embodiment is effective.

  In the present embodiment, each node on the communication system 10 always solves this problem by keeping the data signal receiving unit 15B in an operating state only for a predetermined period (path setting period) set in one cycle. It is characterized by doing.

  This route setting period may be determined in any way as long as it can be known between neighboring nodes, but impulse signals are transmitted and received between neighboring nodes regardless of whether or not they exist on the route. It is easy to determine the path setting period based on the timing at which the impulse signal is transmitted and received.

  In the present embodiment, the period before and after the timing at which the impulse signal is transmitted is set as the path setting period.

  Also in the following description, it is assumed that the forward route and the return route are set between the nodes G, F, A, and C.

(B-1) Configuration and operation of the second embodiment The configuration is different from the first embodiment only in the point relating to the internal configuration of the nodes A to G.

  The internal configuration of the node A of this embodiment is as shown in FIG. 5, for example. The internal configurations of the other nodes B to G are the same as this.

  In FIG. 7, the node A includes an impulse signal receiving unit 11, an impulse signal transmitting unit 13, a tuning determination unit 14, a data signal communication unit 15, a path setting unit 18, a path information storage unit 19, and a communication. Timing calculation means 20.

  Among these, the functions of the constituent elements 11, 13 to 15, 18, and 19 given the same reference numerals as those in FIG. 1 are basically the same as those in the first embodiment, and thus detailed description thereof is omitted. Although not shown in FIG. 7, the node A of the present embodiment may include the time slot width measuring unit 16 and the angular velocity changing unit 17 having the same functions as those of the first embodiment. Of course.

  The communication timing calculation unit 20 basically has the same function as the communication timing calculation unit 12 of the first embodiment, but is different in that it includes a calculation unit 20A and a reception timing storage unit 20B.

  The reception timing storage unit 20B is mainly a software function body that is generated in the same number as the number of nodes that perform phase interaction with the own node A (that is, neighboring nodes). As an example, one reception timing storage unit 20B can be realized as one row (for example, L1) of a table like the table TB1 shown in FIG.

  The calculation unit 20A executes calculation related to reception timing. This calculation includes, for example, a calculation based on expressions (A1) and (A2) described later.

  FIG. 7A shows an example of the steady state, but the points where the neighboring nodes A to F transmit and receive the impulse signal are the same even in the phase interaction in the transient state. Further, in the transient state, in the state close to the steady state, the phase position of the impulse signal transmitted by each node is close to that in the steady state.

  The calculation unit 20A receives the impulse signal transmitted from the nearby nodes B to F via the impulse signal receiving means 11 in the own node A, and the received phase position and the phase in which the own node A transmits the impulse signal. The time corresponding to the phase difference from the position is stored in each reception timing storage unit 20B as the reception prediction time. For example, if each neighboring node transmits an impulse signal only once during one cycle (the time from immediately after node A transmits an impulse signal until node A transmits the next impulse signal), one cycle It is possible to easily obtain the number of neighboring nodes from the number of impulse signals that can be received, and to generate the same number of reception timing storage units 20B. In addition, the predicted reception time can be stored in each reception timing storage unit 20B.

  Each reception timing storage unit 20B may be given a node number for uniquely identifying each neighboring node only within the node A. Of course, if the address of a neighboring node is found, that address can also be used as the node number.

  If the neighboring nodes of the node A are the same nodes B to F as in the first embodiment, five reception timing storage units 20B are generated in the communication timing calculation unit 20.

  If the operation of storing the predicted reception time in the reception timing storage unit 20B is continued for one cycle, the reception prediction time is stored in all the five reception timing storage units 20B. When shifting from the transient state to the steady state, the phase difference usually fluctuates. Therefore, when it is desired to start transmission / reception of the data signal immediately after the steady state is reached, the five reception timings until the steady state is reached. It is necessary to continue the operation of storing the predicted reception time in the storage unit 20B.

  When the steady state is reached, the phase difference does not fluctuate stably. Therefore, if it is not necessary, the tuning determination means 14 does not store the reception prediction time in the transient state, and the tuning determination means 14 indicates that the steady state has been reached. After the determination, it is efficient to start measuring the phase difference (reception predicted time) and storing it in the reception timing storage unit 20B.

  In the first embodiment, the data signal receiving unit 15B is inoperative in the time slots of nodes other than neighboring nodes on the route. In this embodiment, impulse signals are transmitted to all neighboring nodes. Since the phase position is managed as the predicted reception time, a predetermined time width before and after the predicted reception time (that is, the path setting period) is data regardless of whether or not it exists on the path. The signal receiving means 15B can be put into an operating state. Accordingly, a node (for example, A) existing on the set route can receive a route setting request signal from the node (for example, E) not existing on the route during the route setting period.

  In order to increase the utilization efficiency of various resources in the node, the route setting period should be short, but the route setting request signal needs to be reliably transmitted and received. Therefore, the time width tw1 of one route setting period may be determined based on the following equation (A1).

tw1 = 2 × t1 + t2 (A1)
Here, t1 is a value larger than the minute parameter ε, which is a steady state determination value, and t2 is the shortest time during which the information amount of the maximum value of the size variation range of the path setting request signal can be received. Therefore, the value of t2 is determined depending on the data transmission rate between neighboring nodes.

  Also, for each path setting period, the reception timing tm1 at which the data signal receiving means 15B is in the operating state is determined based on the following equation (A2).

  tm1 = local node impulse signal transmission time + reception predicted time−t1 (A2) That is, the node A receives the data signal reception means at every reception timing tm1 indicated by the formula (A2) (if it is in a non-operational state at that time). 15B is set as an operating state, and the operating state is returned to the non-operating state after the time width tw1 indicated by the formula (A1) has elapsed. If the time slot corresponds to a neighboring node on the route, it is naturally not necessary to return to the non-operating state after the time width tw1 has elapsed.

  The route setting period determined by the equations (A1) and (A2) is effective before and after route setting.

  Therefore, the operation of the node A in this embodiment can be summarized in FIGS.

  FIG. 6A shows the time slots ATS to FTS for one period arranged side by side in order.

  As shown in FIG. 6B, the node A sets the path setting period in the vicinity of the timing at which the nodes A to F transmit the impulse signal according to the equation (A2). Regardless of whether or not it is on the route, if necessary, a route setting request signal can be transmitted during this route setting period and delivered to node A on the route as shown in FIG. When a route setting signal is delivered from the node A to the neighboring node, the transmission timing is set at the head of the time slot ATS of the node A regardless of whether the neighboring node is on the route. Overlapping part of the service period.

  Here, each node including the node A itself transmits a route setting request signal in its own time slot. For example, the node B transmits a path setting request signal at a phase position corresponding to the time width tw1 in the time slot BTS. Naturally, the route setting request signal may be transmitted by the node B as an original transmission source or may be transmitted for relaying.

  After the above-described forward and return paths are set between the nodes G, F, A, and C, the reception timing of the node A is as shown in FIG.

  When a route is set, predetermined information (setting identifier) may be registered in the corresponding reception timing storage unit 20B to indicate that the route has been set.

  In this case, at the reception timing at which the setting identifier is registered, not only before and after the impulse signal, but also a period until the next impulse signal is received (almost almost like the time slot CTS or FTS in FIG. 6D) (almost). 1 time slot), the data signal receiving means 15B is put into an operating state based on the contents stored in the reception timing storage section 20B.

(B-2) Effect of Second Embodiment According to the present embodiment, an effect substantially equivalent to the effect of the first embodiment can be obtained.

  In addition, in the present embodiment, since it becomes possible to deliver a route setting request signal from a node (for example, E) that does not exist on the set route to a node (for example, A) that exists on the route, The flexibility of route setting is increased and the flexibility is high.

(C) Other Embodiments In the first and second embodiments described above, the case where the number of neighboring nodes is mainly six has been described. However, the number of neighboring nodes may be smaller or larger than six. It is natural to be good.

  Although FIG. 10 shows a circular cover area, it is a matter of course that the shape of the cover area is not necessarily circular. The shape of the cover area is mainly determined by the directivity of the antenna mounted on each node and used for transmission and reception of radio signals (impulse signals and data signals).

  In the first embodiment, the route is set in the forward direction and the return direction. However, it is also possible to perform the setting in only one of the directions.

  For example, depending on the type of communication application, bi-directional transmission of user data and exchange of control signals for user data delivery confirmation may be omitted. For example, it is possible to set a route only in the forward direction.

  Furthermore, the configuration of the route information table TB1 in FIG. 4 can be changed.

  For example, as the reception timing, information other than the value indicating what number is seen from the time slot ATS of the node A described above can be used. In the steady state, the time width (impulse signal interval) of each time slot is stable. For example, the time from when the node A transmits the impulse signal to the impulse signal (or time slot) is used. You can also.

  In addition, the initial transmission source can be omitted. Since only the corresponding node (for example, C) transmits a data signal to the corresponding time slot (for example, CTS), even if the initial transmission source is omitted from the path information table TB1, it functions without contradiction. Probability is high.

  In the second embodiment, the path setting period is set before and after the impulse signal. However, as already described, the path setting period can be set to other phase positions.

  In the above description, most of the components realized in hardware can be realized in software, and almost all components realized in software can be realized in hardware. Is possible.

It is the schematic which shows the internal structural example of the node used by 1st Embodiment. It is the schematic which shows the example of whole structure of the communication system concerning 1st and 2nd embodiment. It is the schematic of the time chart which shows operation | movement of 1st Embodiment. It is the schematic which shows an example of the path | route information table used in 1st Embodiment. It is the schematic which shows the internal structural example of the node used by 2nd Embodiment. It is the schematic of the time chart which shows operation | movement of 2nd Embodiment. It is the schematic which shows 1 period of the time slot used in 1st and 2nd embodiment. It is the schematic which shows another whole structure example (arrangement example of a node) in the communication system concerning 1st Embodiment. It is explanatory drawing of the tuning between nodes in the communication system of 1st Embodiment. It is explanatory drawing of the tuning between nodes in the communication system of 1st Embodiment. It is explanatory drawing which shows the example of a change of the time slot width before and behind the phase shift of 1st Embodiment. It is explanatory drawing which shows the content of the phase signal before and behind the phase shift of 1st Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Communication system, 11 ... Impulse signal receiving means, 12, 20 ... Communication timing calculation means, 13 ... Impulse signal transmission means, 14 ... Tuning determination means, 15 ... Data signal communication means, 15A ... Data signal transmission means, 15B ... Data signal receiving means, 16 ... Time slot width measuring means, 17 ... Angular velocity changing means, 18 ... Path setting means, 19 ... Path information storage means, 20A ... Calculation part, 20B ... Reception timing storage part, A to G ... Node, RG1, RE1, RF1, RA1, RB1, RD1... Route setting request signal.

Claims (6)

A transmission medium access control apparatus that performs access control on a transmission medium by allowing the own node to access the transmission medium using any of a plurality of time slots that circulate periodically,
A state variable signal communication unit that receives an operation state or operation timing of another node and intermittently transmits a state variable signal that indicates an operation state or operation timing of the own node;
Based on the state variable signal received from the other node received by the state variable signal communication unit, the operation state or operation timing of the own node is transited, and the state variable signal from the own node reflecting this transition is generated to generate the state variable signal. A timing determining unit that recognizes a time slot in which the local node and one or more other nodes in the vicinity where the state variable signal reaches can transmit a data signal;
A data transmission unit that periodically transmits a data signal for each time slot determined by the operation timing of the own node;
A data receiving unit for receiving data signals from other nodes;
A route setting control signal processing unit that generates or relays a route setting control signal including initial transmission source information indicating at least a node that is an initial transmission source;
When the route setting control signal is received from the immediately preceding node that is the immediately preceding transmission source on the relay route of the route setting control signal and the route setting is performed, the operation timing indicated by the state variable signal transmitted by the immediately preceding node is set. A route setting unit for setting reception timing specification information to be specified;
A data reception operation control unit that operates the data reception unit at an operation timing indicated by the reception timing designation information set in the route setting unit without normally operating the data reception unit, Transmission medium access control device. The transmission medium access control device according to claim 1.
Among the routes from the first node that is the initial transmission source to the second node that has received the route setting control signal via one or more other nodes, the second node to the first node In order to set a path in the return direction to the node, when each node on the second node or path that has received the path setting control signal returns a path setting response signal, the response signal A response signal generating unit that generates a signal including at least next hop information indicating a node immediately after the current node on the relay path of the response signal and final destination information indicating the first node;
When the response signal is received via the data receiving unit from the immediately preceding node existing immediately before the own node on the relay path of the response signal, the path setting unit transmits the state variable signal transmitted by the immediately preceding node. A transmission medium access control apparatus, wherein reception timing designation information for designating an operation timing indicated by is set. The transmission medium access control device according to claim 1.
The data reception operation control unit
In order to receive a new route setting control signal for a predetermined route setting time width predetermined in the time width corresponding to the reception timing indicated by the state variable signal transmitted by the other node in the vicinity, A transmission medium access control device characterized by operating a data receiving unit. The transmission medium access control apparatus according to claim 3,
The path setting time width is set to be equal to or less than the upper limit of the fluctuation range related to the data size of the path setting control signal, and the transfer of the path setting control signal between neighboring nodes is executed with a time width equal to or less than the upper limit. A transmission medium access control device. A transmission medium access control method for performing access control on a transmission medium by allowing the own node to access the transmission medium using any one of a plurality of periodically circulated time slots,
The state variable signal communication unit receives the state variable signal indicating the operation state or operation timing of the other node, and intermittently transmits the state variable signal indicating the operation state or operation timing of the own node,
Based on the state variable signal received from the other node received by the state variable signal communication unit, the timing determination unit transitions the operation state or operation timing of the own node, and the state variable signal from the own node reflecting this transition Is generated and given to the state variable signal communication unit, and recognizes a time slot in which the local node and one or more other nodes near the state variable signal can transmit the data signal,
The data transmission unit periodically transmits a data signal for each time slot determined by the operation timing of the own node,
The data receiver receives data signals from other nodes,
The route setting control signal processing unit generates or relays a route setting control signal including initial transmission source information indicating at least a node that is an initial transmission source,
When the route setting unit receives the route setting control signal from the immediately preceding node that is the immediately previous transmission source on the relay route of the route setting control signal and performs route setting, the state variable signal transmitted by the immediately preceding node Set the reception timing specification information that specifies the operation timing indicated by
The data reception operation control unit normally does not operate the data reception unit, and operates the data reception unit at the operation timing indicated by the reception timing designation information set in the path setting unit. Medium access control method. A transmission medium access control program for performing access control on a transmission medium by causing the own node to access the transmission medium using any of a plurality of time slots that circulate periodically.
A state variable signal communication function for receiving a state variable signal indicating an operation state or operation timing of another node and intermittently transmitting a state variable signal indicating an operation state or operation timing of the own node;
Based on the state variable signal received from the other node received by the state variable signal communication function, the operation state or operation timing of the own node is transited, and the state variable signal from the own node reflecting the transition is generated to generate the state variable signal. A timing determination function that recognizes a time slot in which the local node and one or more other nodes in the vicinity where the state variable signal reaches can transmit a data signal;
A data transmission function for periodically transmitting a data signal for each time slot determined by the operation timing of the own node;
A data receiving function for receiving data signals from other nodes;
A path setting control signal processing function for generating or relaying at least a path setting control signal including initial transmission source information indicating a node which is an initial transmission source;
When the route setting control signal is received from the immediately preceding node that is the immediately preceding transmission source on the relay route of the route setting control signal and the route setting is performed, the operation timing indicated by the state variable signal transmitted by the immediately preceding node is set. A route setting function for setting reception timing specification information to be specified;
Normally, the data reception function is not operated, and the data reception operation control function for operating the data reception function is realized at the operation timing indicated by the reception timing designation information set in the path setting function. A transmission medium access control program.

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