KR100983247B1 - Scheduling Method for Transmission Signal of Object - Google Patents

Abstract

The present invention relates to a method of providing a slot number to each object (a) colored by a coloring algorithm, and (b) a slot that is not currently reassigned to an object having the smallest slot number among objects within a reception range of a corresponding sensor. While reassigning the smallest slot number of the numbers, the slot numbers of all objects with the slot number assigned before the reallocation of the object being reassigned and the slot numbers of all objects with the slot number being reassigned are interchanged. Step (c) repeating step (b) for the remaining objects other than the object reallocated in step (b) until slot numbers are reassigned to all objects of the sensor; and (d) Repeating the steps (b) and (c) for the other sensor, the object transmission signal schedule comprising the step of reallocating the slot number to all objects There is provided a method.

In the location system in which a plurality of objects transmit and receive signals to and from a plurality of sensors, a slot number is assigned to each object, and the power consumption of the sensor that needs to receive the signal according to the signal transmission of the objects can be reduced to a minimum. An object transmission signal scheduling method for finding a time slot allocation method for reducing power consumption of a sensor within a short time may be provided by reducing the number of cases of the allocation method to be less than or equal to the factorial number of sensors.

Description

Scheduling Method for Transmission Signal of Object

The present invention relates to an object transmission signal scheduling method, and more particularly, in a location system in which a plurality of objects transmit and receive signals to and from a plurality of sensors, the time slot numbers are assigned to the respective objects. The present invention relates to an object transmission signal scheduling method for finding a slot number allocation method capable of reducing the power consumption of a sensor to be received as close to the minimum as possible.

In a location system in which a plurality of objects transmit and receive a wireless signal with a plurality of sensors, each sensor must receive a transmission signal of objects within a sensing range without collision at regular intervals.

In general, a location system consisting of a plurality of sensors and a plurality of objects is a graph in which each object is represented by a vertex in the topology and the objects whose transmission signals to the same sensor collide with each other are connected by edges. After generating the graph, the graph is colored by a coloring algorithm so that each object is assigned a time slot number.

When a time slot number is assigned, each object is activated (ie, wakes up) only at a time corresponding to the corresponding time slot number per cycle, and transmits a signal to the sensor, and sleeps in a section other than its own time slot interval. ) To reduce power consumption.

In addition, the sensor receives in the wake-up state until the signal of the object with the last slot number assigned among the objects within its reception range, and then sleeps in the time slot period until one cycle ends. To reduce power consumption.

Regarding the above wake-up and sleep states, a case in which a specific sensor is configured to receive signals of objects 1 to 3 in a position system in which one cycle consists of time slots 1 to 5 is described below.

If object 1 is assigned time slot 2, object 2 is assigned time slot 3, and object 3 is assigned time slot 1, object 1 transmits and receives signals only for time slot 2 time per cycle, and timeslots 1 and 3 Is in sleep state, object 2 transmits and receives signal in time slot 3 every 1 cycle, and sleeps in time slot 1 and 2, and object 3 transmits and receives signal in time slot 1 every 1 cycle. In slots 2 and 3, it will sleep.

In addition, the sensor receives a wake-up state from the slot 2, the time slot 3, which is the last slot number, to be allocated, and then goes to sleep in the timeslot 4 and the timeslot 5.

However, if there are a plurality of objects and a plurality of sensors, and the number of time slots in one cycle is large, the time slot numbers are allocated by the existing coloring algorithm and then reallocated time slot numbers for power saving of the sensor. The method is innumerable.

In more detail, such a time slot number reallocation method results in the number of cases corresponding to the factorial number of the number of time slot numbers, and thus, among these many time slot allocation methods, time slot reallocation which minimizes the activation time in one period of the sensor. The problem was finding a way to reassign a time slot reassignment method that minimizes sensor power consumption, no matter how good a computer is.

In other words, if there are 100 time slots, there are 100! (Factorial) time slot reassignment methods, so finding a time slot reassignment method that minimizes sensor power consumption is very time consuming even if calculated by the supercomputer. This is a problem that is practically almost impossible to use.

An object of the present invention for solving the above-described problems, the time slot number is assigned to each object in a location system where a plurality of objects transmit and receive signals with a plurality of sensors, the power consumption of the sensor receiving the signals of the objects The object of the present invention is to provide an object transmission signal scheduling method that finds a time slot allocation method for reducing power consumption in a short time by reducing the number of slot number allocation methods that can be reduced to as close as possible.

In the object transmission signal scheduling method of the present invention for achieving the above object, in the object transmission signal scheduling method in which a plurality of objects transmit a transmission signal to the sensor every one period in any one slot period of the plurality of slot intervals, respectively; (a) A topology of a location system composed of a number of objects and sensors is created as a graph in which each object is represented by vertices and objects whose transmission signals to the same sensor collide with each other. A slot number is assigned to each object by coloring by a coloring algorithm, and (b) for each sensor, slot numbers that are not currently reassigned to an object having the smallest slot number among the objects in the receiving range of the sensor To reallocate the smallest slot number The slot number of all objects having the slot number assigned before the assignment and the slot number of all the objects having the slot number being reassigned are replaced with each other, (c) the slot number is reassigned to all objects of the sensor. Repeat steps (b) for the remaining objects except for the object reallocated in step (b) and (d) repeat steps (b) and (c) for the other sensors, Provided is an object transmission signal scheduling method comprising the step of reallocating slot numbers to objects.

The step (b) is performed from a sensor having a small number of objects whose slot numbers within the reception range are not reassigned. It can be performed from the sensor.

As described above, according to the present invention, a time slot number is assigned to each object in a location system in which a plurality of objects transmit and receive signals to and from a plurality of sensors, and the power consumption of the sensor receiving the signals of the objects is minimized. An object transmission signal scheduling method for finding a time slot allocation method for reducing power consumption in a short time may be provided by reducing the number of cases of slot number allocation method that can be reduced to less than the factorial number of sensors.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

1 is an exemplary diagram illustrating an arrangement state of sensors and objects according to a first embodiment of the present invention.

As shown in FIG. 1, the arrangement state of a plurality of objects that transmit and receive a plurality of sensors and a wireless signal according to the first embodiment of the present invention, the first sensor (S1), the second sensor (S2) and the third sensor S3 and the first object O1, the second object O2, the third object O3, the fourth object O4, the fifth object O5, and the sixth object O6. .

Although three sensors S1 to S3 and six objects O1 to O6 are shown in the present invention, the number of sensors S1 to S3 and objects O1 to O6 is not limited thereto, and is reduced or further increased. Can be.

The first object O1, the second object O2, and the fourth object O4 transmit a signal to the first sensor S1, and the second object O2, the third object O3, and the first object O1. The 5th object O5 and the 6th object S6 transmit a signal to the 2nd sensor S2, and the 3rd object O3 and the 6th object O6 transmit a signal to the 3rd sensor S3. .

2 is a flowchart showing a scheduling method according to a first embodiment of the present invention, FIG. 3 is an exemplary view showing a topology between a sensor and an object according to the first embodiment of the present invention, and FIG. FIG. 5 is a diagram illustrating a slot number assigned to a topology between a sensor and an object according to an embodiment. FIG. 5 is a diagram illustrating a slot number within one period according to the first embodiment of the present invention.

Referring to FIG. 2, in order to schedule a plurality of objects to be allocated to any one slot period among a plurality of slot sections to transmit an object signal to a sensor without collision every cycle, first, a topology and a graph of a location system are formed. (Step S110).

As shown in FIG. 3, each object O1 to O6 is represented by a vertex, and objects O1 to O6 to which signals transmitted to the same sensor collide with each other are referred to as edges. 4 and 5, slot numbers T1, T2, T3, T4, ... within a period T are formed by using a coloring algorithm, as shown in FIGS. Are assigned to the objects O1 to O6 (step S120).

Coloring algorithms are described in D. Johnson, C. Aragon, L. McGeoch, and C. Schonon "Optimization by simulated annealing: an experimental evaluation; part 2, graph coloring and number partitioning," Operations Research, vol. 39, pp. 378-406, 1991. "and D. Brelaz," New methods to color the vertices of a graph, "Communications of the ACM, vol. 22, pp. 251-256, Apr. As it is used in two papers, such as 1979. "

Subsequently, the slot number is not reassigned to the objects within the receiving range of the sensor while the slot number is assigned to each object within the receiving range of the sensor through existing coloring algorithms such as 'GREEDY' and 'DSATUR'. The sensor is selected (step S130).

Subsequently, the smallest slot number among the slot numbers which are not currently reassigned is reassigned to the object having the smallest slot number among the objects within the reception range of the corresponding sensor (step S140).

The slot numbers of all objects having the slot number assigned before the reallocation of the object to be reallocated and the slot numbers of all the objects having the slot number reallocated are exchanged with each other.

In this way, until the slot number is reassigned to all objects in the reception range of the selected sensor, the object with the smallest slot number among the objects in the reception range of the selected sensor for the remaining objects except the reallocated object. Reassign the smallest slot number among the slot numbers that are not currently reallocated.

Then, the process of swapping the slot numbers of all the objects having the slot numbers assigned before the reallocation of the reallocated objects and the slot numbers of all the objects having the reallocated slot numbers are repeated (step S150).

In this way, if slot numbers are reassigned to all objects within the receiving range of the selected sensor, slot numbers that are not currently reassigned to the object with the smallest slot number among the objects within the receiving range of the selected sensor for other sensors as well. Reallocate the smallest slot number.

Then, the process of swapping the slot numbers of all the objects having the slot numbers assigned before the reallocation of the reallocated objects and the slot numbers of all the objects having the reallocated slot numbers are repeated (step S160).

In this way, when the slot number is reallocated to the objects within the reception range of all sensors, the reassignment process is terminated.

6 is an exemplary diagram illustrating a scheduling method according to a first embodiment of the present invention, and FIG. 7 is a diagram illustrating a state in which a slot number is reassigned to a topology between a sensor and an object in a scheduling method according to a first embodiment of the present invention. It is an exemplary figure to show.

Next, an example of the scheduling method according to the first embodiment of the present invention is shown.

First, as shown in FIG. 6 (a), a slot number is assigned to each object O1 to O6 within a reception range of a sensor through existing coloring algorithms such as 'GREEDY' and 'DSATUR'. The first object (O1) to which the first slot (T1) among the first sensor (S1), the second sensor (S2), and the third sensor (S3) to which the slot number is not reassigned to the objects within the reception range of the The first sensor S1 receiving the signal of the second object O2 assigned to the fourth slot T4 and the fourth object O4 assigned to the second slot T2 is first selected.

However, the second object O2 to which the fourth slot T4 is assigned, the third object O3 to which the second slot T2 is assigned, the fifth object O5 to which the first slot T1 is assigned, and The second sensor S2 receiving the signal of the sixth object O6 to which the third slot T3 is allocated or the third object O3 to which the second slot T2 is assigned or the third slot T3 The third sensor S3 that receives the signal of the allocated sixth object O6 may be selected first.

Subsequently, the smallest slot number T1 among slot numbers not currently reassigned to the first object O1 having the smallest slot number among the objects O1, O2, and O4 within the reception range of the first sensor S1. ), The slot number T1 of all the objects 01 and 05 having the slot number T1 assigned before the reallocation of the object O1 to be reallocated, and the slot number T1 to be reallocated. The slot numbers of all the objects (01, 05) that have a value are interchanged.

That is, as shown in FIG. 6 (b), the current object is re-presented in the first object O1 having the smallest slot number T1 among the objects O1, O2, and O4 within the reception range of the first sensor S1. Reallocates the smallest slot number T1 among the unallocated slot numbers.

However, the slot number T1 of all the objects O1 and O5 having the slot number T1 assigned before the reallocation of the first object O1 to be reassigned, and the slot number T1 to be reallocated. Since the slot numbers T1 of all the objects O1 and O5 are the same, there is no change.

Therefore, the first slot T1 is reassigned to the first object O1 and the fifth object O5.

Subsequently, the first slot T1 is currently reassigned to the fourth object O4 having the smallest slot number among the second object O2 and the fourth object O4 except for the first object O1 that is reassigned. The slot number of all objects 03 and O4 having the slot number T2 assigned before the reallocation of the object O4 to be reallocated, while reassigning the smallest slot number T2 among the unscheduled slot numbers. T2) and the slot numbers T2 of all the objects 03 and 04 having the slot numbers T2 to be reallocated are exchanged with each other.

That is, as shown in FIG. 6 (c), the current object is not reassigned to the fourth object O4 having the smallest slot number T2 among the objects O2 and O4 within the reception range of the first sensor S1. Reallocates the smallest slot number T2 among the slot numbers.

However, the slot number T2 of all objects O3 and O4 having the slot number T2 assigned before the reallocation of the fourth object O4 to be reallocated, and the slot number T2 to be reallocated. Since the slot numbers T2 of all the objects O3 and O4 are the same, there is no change.

Therefore, the second slot T2 is reassigned to the third object O3 and the fourth object O4.

Subsequently, the slots not currently reassigned to the second object O2 except for the first object O1 to which the first slot T1 is reassigned and the fourth object O4 to which the second slot T2 is reassigned. The slot number T4 of all the objects O2 having the slot number T4 assigned before the reallocation of the object O2 to be reallocated while reassigning the smallest slot number T3 among the numbers, The slot numbers of all the objects O6 with the slot number T3 to be assigned are interchanged.

That is, as shown in FIG. 6 (d), the smallest slot number T3 among the slot numbers not currently reassigned is reassigned to the second object O2 within the reception range of the first sensor S1.

The object O6 having the slot number T4 of the object O2 having the slot number T4 assigned before the reallocation of the second object O2 to be reassigned and the slot number T3 being reallocated. Slot number T3 is replaced with each other.

Accordingly, the third slot T3 is reassigned to the second object O2, and the slot number assigned to the sixth object O6 is changed from the third slot T3 to the fourth slot T4.

Subsequently, the second object O2, the third object O3, and the fifth object O5 among the objects O2, O3, O5, and O6 within the reception range of the second sensor S2, which are other sensors, are reconstructed. Since it has been allocated (step S130), the smallest slot number T4 among the slot numbers not currently reallocated with respect to the sixth object O6 is reassigned, and has been assigned before the reallocation of the object O6 being reassigned. The slot number T4 of all the objects O6 with the slot number T4 and the slot number of all the objects O6 with the slot number T4 being reallocated are exchanged with each other.

That is, as shown in FIG. 6E, the smallest slot number T4 among the slot numbers that are not currently reassigned to the sixth object O6 within the reception range of the second sensor S2 is reassigned. Since the slot number T4 assigned before the reallocation of the sixth object O6 to be reallocated is the same as the slot number T4 of the object O6 having the slot number T4 to be reallocated, there is no change. Therefore, the fourth slot T4 is reassigned to the sixth object O6.

Subsequently, the second object O2 and the sixth object O6 within the reception range of the third sensor S3, which is another sensor, are reassigned earlier, and thus the reassignment process is completed.

Thus, as shown in FIG. 7, the first slot T1 in the first object O1, the third slot T3 in the second object O2, and the second slot T2 in the third object O3. The fourth slot T4 is reassigned to the second slot T2 to the fourth object O4, the first slot T1 to the fifth object O5, and the fourth slot T4 to the sixth object O6, respectively. Thus, slot numbers are reassigned to all objects O1 to O6 within a reception range of the first sensor S1, the second sensor S2, and the third sensor S3.

In the scheduling method according to the first embodiment of the present invention as described above, the reassignment step may be performed from any one of the first sensor S1, the second sensor S2, and the third sensor S3. The number of cases where the slot allocation method corresponds to the factorial number of the number of sensors is obtained. Therefore, a small number of slot allocation methods are derived regardless of the number of slots.

8 is a flowchart illustrating a scheduling method according to a second embodiment of the present invention.

Referring to FIG. 8, in order to schedule a plurality of objects to be allocated to any one slot period among a plurality of slot sections to transmit an object signal to a sensor without collision every cycle, first, a topology and a graph of a location system are formed. (Step S210).

As shown in FIG. 3, each object O1 to O6 is represented by a vertex, and objects O1 to O6 to which signals transmitted to the same sensor collide with each other are referred to as edges. 4 and 5, slot numbers T1, T2, T3, T4, ... within a period T are formed by using a coloring algorithm, as shown in FIGS. Are assigned to the objects O1 to O6 (step S220).

Subsequently, in the state where the slot number is assigned to each object within the receiving range of the sensor through existing coloring algorithms such as 'GREEDY' and 'DSATUR', the slot number is not reassigned to the objects within the receiving range of the sensor. Among them, a sensor having a small number of objects within a reception range of the sensor is selected (step S230).

Subsequently, the smallest slot number among the slot numbers not currently reassigned is reassigned to the object having the smallest slot number among the objects within the reception range of the sensor (step S240).

The slot numbers of all objects having the slot number assigned before the reallocation of the object to be reallocated and the slot numbers of all the objects having the slot number reallocated are exchanged with each other.

In this way, until the slot number is reassigned to all objects in the reception range of the selected sensor, the object with the smallest slot number among the objects in the reception range of the selected sensor for the remaining objects except the reallocated object. Reassign the smallest slot number among the slot numbers that are not currently reallocated.

Then, the process of swapping the slot numbers of all the objects with the slot numbers assigned before the reallocation of the reallocated objects and the slot numbers of all the objects with the reallocated slot numbers are repeated (step S250).

In this way, if the slot number is reassigned to all objects in the reception range of the selected sensor, the slot number of the smallest slot among the objects in the reception range of the sensor is in the order of the number of objects in which the slot number in the reception range is not reallocated. Reallocates the smallest slot number among the slot numbers that are not currently reassigned to the object with.

Then, the process of swapping the slot numbers of all the objects having the slot numbers assigned before the reallocation of the reallocated objects and the slot numbers of all the objects having the reallocated slot numbers are repeated (step S260).

In this way, when the slot number is reallocated to the objects within the reception range of all sensors, the reassignment process is terminated.

9 is a diagram illustrating a scheduling method according to a second embodiment of the present invention. FIG. 10 is a diagram illustrating a state in which a slot number is reassigned to a topology between a sensor and an object by a scheduling method according to a second embodiment of the present invention. It is an exemplary figure to show.

Next, an example of the scheduling method according to the second embodiment of the present invention is shown.

First, as shown in FIG. 9 (a), a slot number is assigned to each object O1 to O6 within a receiving range of a sensor by an existing coloring algorithm such as 'GREEDY' and 'DSATUR'. The third object O3 to which the second slot T2 is allocated among the first sensor S1, the second sensor S2, and the third sensor S3 and the sixth object O6 to which the third slot T3 is assigned The first sensor (S3) for receiving the transmission signal of the first) is selected first.

Subsequently, the smallest of the slot numbers not currently reassigned to the third object O3 having the smallest slot number among the third object O3 and the sixth object O6 within the reception range of the third sensor S3. The slot number T2 of all the objects O3 and O4 having the slot number T2 assigned before the reallocation of the object O3 to be reallocated while reassigning the slot number T1, and the slot to be reallocated. The slot numbers T1 of all the objects O1 and O5 having the number T1 are interchanged.

That is, as shown in FIG. 9B, the smallest slot number T1 among the slot numbers not currently reassigned is reassigned to the third object O3 within the reception range of the third sensor S3.

The slot number T2 of all objects O3 and O4 having the slot number T2 assigned before the reallocation of the third object O3 to be reassigned and the slot number T1 to be reallocated. The slot numbers T1 of all the objects O1 and 05 are interchanged.

Therefore, the slot numbers allocated to the first object O1 and the fifth object O5 are changed from the first slot T1 to the second slot T2. The slot number assigned to the fourth object O4 is changed from the second slot T2 to the first slot T1.

Thus, the first slot T1 is reassigned to the third object O3 and the fourth object O4.

Subsequently, the first slot T1 reallocates the smallest slot number T2 among the slot numbers that are not currently reassigned to the sixth object O6 except for the third object O3 that is reassigned. The slot number T3 of all objects O6 having the slot number T3 assigned before the reallocation of the object O6, and the all objects O1 and O5 having the slot number T2 being reassigned. The slot number T2 is interchanged.

That is, as shown in FIG. 9C, the smallest slot number T2 among the slot numbers that are not currently reassigned to the sixth object O6 within the reception range of the third sensor S3 is reallocated. do.

Then, all objects having the slot number T3 of all the objects 06 having the slot number T3 assigned before the reallocation of the sixth object O6 to be reallocated and the slot number T2 being reallocated. The slot numbers T2 of (01, 05) are interchanged.

Therefore, the slot numbers allocated to the first object O1 and the fifth object O5 are changed from the second slot T2 to the third slot T3.

The slot number assigned to the sixth object O6 is changed from the third slot T3 to the second slot T2. Thus, the second slot T2 is reassigned to the sixth object O6.

Subsequently, the fourth object O4 among the objects O1, O2, and O4 within the reception range of the first sensor S1, which is another sensor, is reassigned earlier, and thus the fourth object to which the first slot T1 is reassigned. The smallest slot number T3 among slot numbers not currently reassigned to the first object O1 having the smallest slot number among the first object O1 and the second object O2 except for (O4) Allocating, all slots (T3) of all objects (O1, O5) having the slot number (T3) assigned before the reallocation of the object (O3) to be reassigned, and all slots (T3) to be reallocated. The slot numbers T3 of the objects O1 and O5 are interchanged.

That is, as shown in FIG. 9 (d), currently not reassigned to the first object O1 having the smallest slot number T3 among the objects O1 and O2 within the reception range of the first sensor S1. Reallocates the smallest slot number T3 among the unscheduled slot numbers.

However, the slot numbers T3 of all the objects O1 and O5 having the slot number T3 assigned before the reallocation of the first object O1 to be reassigned and the slot number T3 to be reallocated. Since the slot numbers T3 of all the objects O1 and O5 are the same, there is no change.

Therefore, the third slot T3 is reassigned to the first object O1 and the fifth object O5.

Subsequently, a slot that is not currently reassigned to the second object O2 except for the first object O1 to which the third slot T3 is reassigned and the fifth object O5 to which the first slot T1 is reassigned. The slot number T4 of all the objects O2 having the slot number T4 assigned before the reallocation of the object O2 to be reallocated while reassigning the smallest slot number T4 among the numbers, The slot numbers of all the objects O2 having the slot number T4 to be allocated are interchanged.

That is, as shown in FIG. 9E, the smallest slot number T4 among slot numbers not currently reassigned is reassigned to the second object O2 within the reception range of the first sensor S1. However, the slot number T4 of all the objects O2 having the slot number T4 assigned before the reallocation of the second object O2 to be reallocated, and all the objects having the slot number T4 reallocated. Since the slot numbers T4 of the (O2) s are the same, there is no change. Therefore, the fourth slot T4 is reassigned to the second object O2.

Subsequently, the second object O2, the third object O3, the fifth object O5, and the sixth object O6 within the reception range of the second sensor S2, which are other sensors, are reassigned, The assignment process is complete.

Thus, as shown in FIG. 10, the third slot T3 in the first object O1, the fourth slot T4 in the second object O2, and the first slot T1 in the third object O3. The first slot T1 is assigned to the fourth object O4, the second slot T2 is assigned to the third slot T3, and the sixth object O6 to the fifth object O5, respectively.

Thus, slot numbers are reassigned to all objects O1 to O6 within a reception range of the first sensor S1, the second sensor S2, and the third sensor S3.

According to the scheduling method according to the second embodiment of the present invention described above, since the slot reassignment step is performed from the sensor having the smallest number of objects whose slot numbers in the reception range are not reallocated, the number of objects in the reception range of the sensor If all of the sensors are different, only one case is generated. If the number of objects in the receiving range of the sensor is the same for each sensor, the number of cases corresponding to the number of factorials of the sensor is generated.

Therefore, according to the second embodiment of the present invention, since there is a slot allocation method of less than the factorial number of sensors, there are fewer slot allocation methods than the first embodiment of the present invention.

FIG. 11 is a graph illustrating a state in which a wake up time, that is, an activation time of a sensor is compared between a scheduling method and a conventional scheduling method according to the second embodiment of the present invention.

In the graph of FIG. 11, 'GREEDY' and 'DSATUR' are sensor wake-up times with respect to an alpha (α) value of an object according to a scheduling method randomly assigned through the coloring scheme, and 'GREEDY + MFP' is 'GREEDY'. 'Is the sensor wake-up time relative to the alpha value of the object to which the scheduling method according to the second embodiment of the present invention is applied in a colored manner. 'DSATUR + MFP' is a sensor wake-up time compared to an alpha value of an object to which the scheduling method according to the second embodiment of the present invention is applied in the 'DSATUR' color scheme.

Here, the alpha value is a value obtained by dividing an interference range radius by a transmission range radius, and more specifically, the sensor wake-up time is more precisely, among time slot numbers allocated by objects belonging to a sensor reception range. The largest number is the sum of all the sensors. Since the sensors must each be in the wake-up state until receiving the transmission signal of the object assigned the last slot number among the objects within the reception range, the last slot number itself is the sensor wake-up time.

As shown in FIG. 11, when the scheduling method according to the second embodiment of the present invention is used, it is confirmed that the sensor wake-up time is reduced in all alpha values, compared to the case in which the slot is arbitrarily assigned by the existing coloring algorithm. have.

Accordingly, according to the second embodiment of the present invention, the time slot allocation method for reducing the power consumption is reduced by reducing the number of slot number allocation methods that can reduce the sensor power consumption as close to the minimum as possible. You can find it in a short time.

In the above description, the present invention has been described with reference to preferred embodiments, but the present invention is not necessarily limited thereto, and a person having ordinary skill in the art to which the present invention pertains does not depart from the technical spirit of the present invention. It will be readily appreciated that various substitutions, modifications and variations can be made.

1 is an exemplary view showing an arrangement state of sensors and objects according to a first embodiment of the present invention;

2 is a flowchart illustrating a scheduling method according to a first embodiment of the present invention;

3 is an exemplary view showing a topology between a sensor and an object according to a first embodiment of the present invention;

4 is an exemplary diagram illustrating a state where a slot number is assigned to a topology between a sensor and an object according to a first embodiment of the present invention;

5 is an exemplary diagram showing a slot number within one period according to the first embodiment of the present invention;

6 is an exemplary view showing a scheduling method according to a first embodiment of the present invention;

7 is an exemplary diagram illustrating a slot number reassigned to a topology between a sensor and an object in a scheduling method according to the first embodiment of the present invention;

8 is a flowchart illustrating a scheduling method according to a second embodiment of the present invention;

9 is an exemplary view showing a scheduling method according to a second embodiment of the present invention;

FIG. 10 is an exemplary diagram illustrating a slot number reassigned to a topology between a sensor and an object in a scheduling method according to a second embodiment of the present invention; FIG.

11 is a graph illustrating a state in which a wake-up time of an object is compared between a scheduling method and a conventional scheduling method according to a second embodiment of the present invention.

Claims (2)

A method of scheduling an object transmission signal in which a plurality of objects transmit transmission signals to sensors in a period of one slot of each of a plurality of slot sections, each sensor; (a) Topology of a location system made up of a number of objects and sensors, each of which is represented by a vertex and objects whose transmission signals to the same sensor collide with each other are created as graphs connected by edges. And the graph is colored by a coloring algorithm to give each object a slot number; (b) reallocating the reallocated object by reassigning the smallest slot number among the slot numbers that are not currently reassigned to the object having the smallest slot number among the objects within the reception range of the corresponding sensor for each sensor; Changing slot numbers of all objects having previously assigned slot numbers and slot numbers of all objects having slot numbers reassigned; (c) repeating step (b) for the remaining objects except the object reallocated in step (b) until slot numbers are reassigned to all objects of the sensor; And (d) repeating steps (b) and (c) for the other sensor, and reassigning slot numbers to all objects; Object transmission signal scheduling method comprising a. The method of claim 1, The step (b) is performed from a sensor having a small number of objects whose slot numbers within the reception range are not reassigned. Object transmission signal scheduling method characterized in that performed from the sensor.

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