KR20090106033A - Transmitting device, receiving device and transmitter-receiver system in wireless sensor network - Google Patents

Abstract

PURPOSE: A transmission device of a sensor network, a receiving device and a transceiving system are provided to reduce the number of times of transmitting preambles. CONSTITUTION: A transmission device(100) of a sensor network includes a preamble generator and a preamble ack handler. The preamble generator(111) determines the time when a preamble is generated and transmitted to a receiving device and the transmission repetition interval of the preamble by using a prediction error information stored during the previous packet transmission. The preamble ack handler(113) generates data packet when an ack signal is received from the receiving device and then transmits it.

Description

Transmitter, Receiver and Transmit System in Sensor Networks {TRANSMITTING DEVICE, RECEIVING DEVICE AND TRANSMITTER-RECEIVER SYSTEM IN WIRELESS SENSOR NETWORK}

The present invention relates to a sensor network, and more particularly, to a transmitting device, a receiving device, and a transmitting and receiving system of a sensor network capable of minimizing power consumption in a sensor network performing periodic data transmission with low duty cycle.

Recently, research on wireless sensor networks has been actively conducted. The sensor network is composed of a wireless sensor network through a sensor node equipped with a sensor that can detect recognition information about an object or surrounding environment information, and the information input through various sensors in real time through an external network. It refers to the processing and management of information by connecting to it.

Ultimately, sensor networks are designed to provide computing and communication functions to all things to enable an environment that can communicate anytime, anywhere, regardless of network, device, or service.

1 is a general configuration diagram of a sensor network. The sensor network transmits sensor nodes 10 including sensor nodes and a communication module that detects recognition information about an object or surrounding environment information in real time, and information collected by the sensor node 10. A sink node 20 includes a gateway 30 for routing information transmitted from the sink node 20 to the management server 40 through a broadband communication network.

The sensor nodes 10 transmit and receive data to each other through a short range wireless communication (WPAN) method such as ZigBee, Ultra Wide Band (UWB), or Bluetooth, and the sink node 20 is a satellite communication, wireless LAN, Bluetooth, The gateway 30 may be connected to an existing infrastructure such as a wired internet.

In this sensor network environment, the sensor field is relatively simple. That is, only some sensors of a limited number can be installed in each of the source nodes 11 installed in one sensor field, and the length of the data packet generated by this is also limited to several types.

In the case of IEEE 802.15.4 (WPAN; ZigBee), a MAC protocol used in the sensor network, the beacon frame, the data frame, the acknowledgment frame, and the MAC command frame It has four formats. In the above case, the acknowledgment frame has a fixed length, and the data frame has a relatively fixed length due to the limitation of the type of sensor used. In addition, the beacon frame and the command frame have a fixed form of the sensor field, which is often fixed, and has only a few simple packet lengths.

2 is a diagram showing the configuration of a transmitting node and a receiving node of the conventional sensor node, respectively. That is, the MAC (Media Access Control) protocol configuration of the sensor nodes 10 is shown.

In FIG. 1, a node transmitting data among the sensor nodes 10 is called a transmitting node 11, and a node receiving data from the transmitting node 11 is called a receiving node 15. A node having a sensor among the transmitting nodes 11 is also called a source node.

The MAC protocol of a sensor node is mainly composed of a receiving module and a transmitting module. In the case of a source node among sensor nodes, a receiving module is not necessary and consists only of a transmitting module. Other sensor nodes include a receiving module and a transmitting module. have.

The transmitting module 12 of the transmitting node 11 is composed of a preamble generator 12-1, a preamble ack handler 12-2, and a packet ack handler 12-3, and a receiving node 15 The receiving module 16 of the preamble handler 16-1 and the packet handler 16-2.

When data to be transmitted by the transmitting node 11 is generated, the transmitting module 12 generates and transmits a preamble in order to know when the receiving node wakes up in the preamble generator 12-1.

The preamble ack handler 12-2 checks whether there is an ack (acknowledge) for the preamble generator 12-1 after generating and transmitting the preamble, and if ack is received from the receiving node 15 within a specified time, Create a packet and send it.

The packet ack handler 12-3 checks whether the data packet ack arrives for a predetermined time after the preamble ack handler 12-2 transmits the packet. When the ack arrives from the receiving node 15, the packet ack handler 12-2 removes the packet from the buffer. The transfer job ends.

The preamble handler 16-1 of the receiving node 15 always checks whether a preamble having its own destination node exists in the wakeup state and, if present, generates a preamble ack and transmits the preamble ack to the corresponding transmitting node 11. The packet handler 16-2 receives a packet transmitted by the transmitting node 11, generates an ack packet for the packet, and transmits the packet to the corresponding transmitting node 11.

The transmitting module of the receiving node 15 serves to transmit data to other sensor nodes or sink nodes.

3 is a diagram illustrating an example of data transmission between a conventional transmitting node and a receiving node, in which a hatched portion represents listening or receiving or a period thereof, and a black portion represents transmitting or a period thereof.

As can be seen in FIG. 3, all the sensor nodes have a predetermined wakeup period and periodically sleep and wakeup.

When the receiving node 15 wakes up, the preamble handler 16-1 checks whether there is a preamble destined for itself for a predetermined listening period. If it does not exist, it goes back to sleep.

If there is data to be transmitted, the transmitting node 11 does not know when the corresponding receiving node 15 is in the wake-up state, and thus the preamble generator 12-1 sends a preamble to search for it. At this time, the preamble includes an address for the corresponding receiving node 15.

When the preamble handler 16-1 of the receiving node 15 successfully receives a preamble of which the node is the destination node, the preamble handler 16-1 generates an ack for the preamble and transmits the ack to the corresponding transmitting node 11.

The transmitting node 11 that transmits the preamble waits for the preamble ack for a predetermined time and if it does not arrive, retransmits the preamble again, which is repeated during the wakeup period. If the transmitting node 11 receives the preamble ack, it knows that the receiving node 15 is in the wake-up state, and thus the preamble ack handler 12-2 transmits the actual data packet.

The receiving node 15 waits for a data packet for a predetermined time after transmitting the preamble ack. If it is not received, it abandons the reception and goes back to sleep. If the data packet is successfully received, the packet handler 16-2 generates a packet ack and transmits the packet to the corresponding transmission node 11.

The transmitting node 11 waits for the data packet ack for a predetermined time after transmitting the data packet, and if the packet is successfully received, the packet transmission process is completed. If it fails, it will retransmit the data packet.

In general, since the transmitting node 11 and the receiving node 15 have a time error of approximately 30 ms per second, the transmitting node 11 does not know exactly when the receiving node 15 wakes up. The search requires, on average, half the wakeup period / 2. Since most sensor nodes are asynchronous, more time errors occur over time.

As a result, the energy consumption of the transmitting node can be said to be proportional to the wakeup period. In general, in order to maximize the lifespan of the sensor network, the wakeup period is extended. This characteristic is that when the wakeup period is increased by more than a predetermined value, the transmitting node does not know the wakeup time of the receiving node. Inevitably, the transmission node has a problem that the lifespan of the sensor network is reduced as the energy consumption increases.

An object of the present invention is to provide a transmitting device, a receiving device, and a transmitting / receiving system of a sensor network capable of minimizing power consumption by reducing the number of transmissions of a preamble by relatively accurately identifying a wake-up time of a receiving node.

Another object of the present invention is to provide a transmitting device, a receiving device, and a transmitting / receiving system of a sensor network capable of minimizing power consumption of a transmitting node as the receiving node temporarily increases a duty cycle in a certain area in which a packet is to be transmitted.

It is still another object of the present invention to minimize the power consumption of the receiving node and to maximize the life of the sensor network by delaying the data transmission time points of the transmitting nodes based on a specific transmitting node. To provide a receiving apparatus and a transmission and reception system.

The technical means of the present invention for achieving the above object is, in the transmitting device of the sensor network, the time when the preamble is generated and transmitted to the receiving device, and the prediction error information stored at the time of the previous packet transmission repeating interval of the preamble Preamble generator to determine using; And a preamble ack for generating a data packet when there is an acknowledgment from the corresponding receiver according to the preamble transmission, and if necessary, requesting the receiver to increase a wake-up duty cycle for a predetermined time point for transmitting the packet. And a handler.

In detail, the preamble ack handler generates a data packet by adding transmission time information of a next packet when generating the data packet.

을 아래 수학식에 의해 획득하며, 상기 프리앰블 전송 반복 구간

을 수학식

또는

에 의해 구해진 값 중 더 작은 값으로 결정하는 것을 특징으로 한다.The preamble generator is a preamble transmission repetition interval

Is obtained by the following equation, and the preamble transmission repetition interval

To the equation

or

Characterized in that the smaller value is determined from the value obtained by.

Equation

The receiver checks its battery and memory in response to a request to increase the wake-up duty cycle of the transmitter and stores this value if it can accept the request. It is characterized by raising.

Another technical means of the present invention for achieving the above object is, in the receiving device of the sensor network, in the wake-up (wakeup) state always checks whether there is a preamble as a target node, and if the preamble exists preamble ack A preamble handler for generating and transmitting the generated signal to the transmitter; A packet handler for receiving a packet transmitted by the transmitting apparatus, generating an ack packet for the transmitting apparatus, and transmitting the generated ack packet to the transmitting apparatus, requesting the transmitting apparatus to delay a preamble transmission time for a predetermined time; And a group scheduler that calculates a data transmission time point of each transmitting device and calculates a delay time for the data transmission time point of each transmitting device to provide a packet handler so that the data transmission time of each transmitting device is achieved within a predetermined time period. It is characterized by.

Specifically, the packet handler checks whether the packet transmission can be delayed to the transmitting apparatuses by a predetermined time according to the amount of spare of the battery and the memory of the packet handler, and the information about the delay time of each transmitting apparatus is determined by the group scheduler. The group scheduler checks a packet time last received from each transmitter, and determines a delay time of each transmitter based on the packet time last received.

Another technical means of the present invention for achieving the above object is a sensor network comprising a transmitting device and a sensor node and a sink node including a plurality of extension values, wherein the transmitting device generates a preamble and transmits the preamble to the receiving device. And a preamble generator configured to determine a transmission repetition interval of the preamble by using prediction error information stored in a previous packet transmission. And a preamble ack for generating a data packet when there is an acknowledgment from the corresponding receiver according to the preamble transmission, and if necessary, requesting the receiver to increase a wake-up duty cycle for a predetermined time point for transmitting the packet. A handler;

The receiving apparatus includes: a preamble handler which checks whether a preamble having its own destination node always exists in a wake-up state, and generates and transmits a preamble ack to the corresponding transmitting apparatus when the preamble exists; A packet handler for receiving a packet transmitted by the transmitting apparatus, generating an ack packet for the transmitting apparatus, and transmitting the generated ack packet to the transmitting apparatus, requesting the transmitting apparatus to delay a preamble transmission time for a predetermined time; And a group scheduler that calculates a data transmission time point of each transmitting device and calculates a delay time for the data transmission time point of each transmitting device to provide a packet handler so that the data transmission time of each transmitting device is achieved within a predetermined time period. It is characterized by.

As described above, the present invention can balance energy consumption of a transmitting node and a receiving node to maximize the life of the link, thereby maximizing the life of the sensor network.

의 값에 비례하여 에너지를 소모하기 때문에 에너지 소모를 최소화할 수 있고, 이 때문에 프리앰블 충돌 확률을 낮추어 네트워크의 수명을 최대화할 수 있음과 아울러 신뢰성있는 데이터 전송이 가능한 이점이 있다.In addition, although the existing transmission node consumes energy in proportion to the wakeup period, the transmission node in the present invention

Since energy is consumed in proportion to the value of, energy consumption can be minimized. Thus, it is possible to maximize the life of the network by lowering the preamble collision probability and to provide reliable data transmission.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 4 is a diagram illustrating a configuration of a MAC and MAP protocol of a transmitting node and a receiving node according to the present invention. A node transmitting data among sensor nodes is called a transmitting node 100. The transmitting node 100 A node that receives data from the node is called a receiving node 200.

The MAC protocol of the sensor node is composed of a transmitting module and a receiving module. In the case of a source node having a sensor among the sensor nodes, the receiving module is not necessary and is composed of only the transmitting module, but other sensor nodes (sensor node and sink node). Relay nodes located in between each other includes a receiving module and a transmitting module.

In the case of the receiving node, a plurality of transmitting nodes may be connected to a data transmission path.

In FIG. 4, since the medium access control is performed by the transmitting module 110 and the receiving node 200 by the transmitting module 110 and the receiving module 210, the transmitting module 110 and the receiving node of the transmitting node 100 are illustrated. It will be described with reference to the receiving module 210 of the (200).

The transmitting module 110 of the transmitting node 100 is composed of a preamble generator 111, a preamble ack handler 113, and a packet ack handler 115, the receiving module 210 of the receiving node 200 It consists of a packet handler 213, a preamble handler 211, and a group scheduler 215.

When data to be transmitted in the transmitting node 100 is generated, the preamble generator 111 of the transmitting module 110 generates and transmits a preamble in order to determine when the receiving node 200 wakes up. In addition, the preamble generator 111 according to the present invention uses the prediction error information stored when the previous packet transmission is performed at the time of generating and transmitting the preamble and the preamble section indicating how much the preamble is to be repeated. Decide

The preamble ack handler 113 checks whether there is an ack for the preamble generator 111 after generating and transmitting the preamble, and generates a data packet when an ack (acknowledge) is received from the receiving node 200 within a specified time. send. Here, the preamble ack handler 113 may request the receiving node 200 to temporarily increase the duty cycle for a certain area to transmit a packet so as to reduce energy consumption of the transmitting node 100 if necessary. .

The packet ack handler 115 checks whether the data packet ack arrives for a predetermined time after the preamble ack handler 113 transmits the packet. When the ack arrives from the receiving node 200, the packet ack handler 115 removes the packet from the buffer. It ends.

The preamble handler 211 of the receiving node 200 always checks whether a preamble having its own destination node exists in the wakeup state, and generates a preamble ack to the corresponding transmitting node 100 when the preamble exists. It serves to transmit.

The packet handler 213 receives the packet transmitted by the transmitting node 100 and generates an ack packet for the transmitting node 100 to transmit the packet to the corresponding transmitting node 100. Here, the packet handler 213 may request the transmitting node 100 to delay the preamble transmission time for a predetermined time, and the exact delay time is determined according to the calculation of the group scheduler 215.

The group scheduler 215 calculates the data transmission time of each transmission node 100 connected to the reception node 200 and the data transmission time of each transmission node 100 is achieved within a predetermined time. The delay time for data transmission is calculated and provided to the packet handler 213.

The transmitting module of the receiving node 200 serves to transmit data to other sensor nodes or sink nodes.

5A to 5C are diagrams for explaining a media access control method according to each embodiment of the present invention.

FIG. 5A illustrates a case in which the size of the preamble section is selected to control the minimum preamble section when operating with a fixed duty cycle.

All sensor nodes, including the transmitting node 100 and the receiving node 200, have a common wakeup period and periodically sleep and wakeup. When the receiving node 200 wakes up, the preamble handler 211 of the receiving node 200 checks whether there is a preamble destined for itself for a predetermined listening period. If it does not exist, it goes back to sleep.

When there is data to be transmitted to the receiving node 200, the transmitting node 100 does not know exactly when the receiving node 200 is in a wake-up state, so in order to search for the receiving node 200, the corresponding receiving node (111) Send a preamble containing the address for In this case, the preamble generator 111 should determine the time point at which the preamble is transmitted and how long the preamble period is to be repeated if the preamble ack does not arrive from the receiving node 200, that is, the size of the preamble section.

In general, the size of the preamble period is the same as the wakeup period. However, in the present invention, the size of the preamble section is obtained by Equation 1 below, and the power consumption of the transmitting node 100 can be reduced by transmitting the preamble only during the obtained preamble section. Physical meanings of L, d, and P in Equation 1 are shown in FIG. 6.

That is, FIG. 6 illustrates that the transmitting node 100 predicts a wakeup time of the receiving node 200 as P (predicted wakeup time), and the actual receiving node 200 wakes up after d (prediction error value). The case is shown. L is a value that determines how many times the preamble is repeatedly transmitted, and indicates the size of a section in which the preamble can be transmitted and is called a preamble section.

은 수학식

또는

에 의해서 구해지며, 두 식에 의해 구해진 값 중 더 작은 값을 프리앰블 구간으로 결정하게 된다. Nth preamble section in Equation 1

Is the equation

or

The smaller of the values obtained by the two equations is determined as the preamble interval.

에서, θ는 1초당 발생하는 송신노드(100)와 수신노드(200)의 오차시간으로, 만일 θ가 30㎲이면 송신노드(100)와 수신노드(200)의 최대 오차시간은 4θ가 된다. 이는 각 노드는 기준점을 전후로 2θ의 시간오차가 발생할 수 있기 때문이며, 송신노드(100) 및 수신노드(200) 상호 간에는 최대 120㎲(4θ)의 시간 오차가 발생될 수 있음을 의미한다.Equation

Θ is an error time between the transmitting node 100 and the receiving node 200 that occurs per second. If θ is 30 ms, the maximum error time between the transmitting node 100 and the receiving node 200 becomes 4θ. This is because each node may have a time error of 2θ before and after the reference point, and a time error of up to 120㎲ (4θ) may occur between the transmitting node 100 and the receiving node 200.

에서 웨이크업 예측 오차값인 d는 마이너스 값(웨이크업 예측시간이 실제 웨이크업보다 늦은 경우)이 나올 수 있으므로 절대값을 이용하는 것이 바람직하며, 여기에서 예측 오차값(d)은 실제 웨이크업 시점의 전후에 나타날 수 있으므로 2α를 승산하게 된다. 따라서, 이전의 웨이크업 예측 오차정보를 이용하여 프리앰블 구간을 새로 계산하여 결정하게 된다.Equation

In d, the wakeup prediction error value may have a negative value (when the wakeup prediction time is later than the actual wakeup time). Therefore, it is preferable to use an absolute value, where the prediction error value d is the actual wakeup time. Since it can appear before and after, it multiplies 2α. Therefore, the preamble section is newly calculated and determined using the previous wakeup prediction error information.

The preamble generator 111 of the transmitting node 100 controls the preamble transmission by determining a time point and a preamble section in which the preamble is transmitted.

On the other hand, when the preamble handler 211 of the receiving node 200 successfully receives a preamble whose destination node is the preamble handler, the preamble handler 211 generates an ack for the preamble and transmits the ack to the corresponding transmitting node 100. .

동안 반복된다.However, the transmitting node 100 having transmitted the preamble waits for the preamble ack for a predetermined time, and if the preamble ack does not arrive, retransmits the preamble again. This is not a wake-up period, but the preamble section obtained in Equation 1 above.

Is repeated.

When the preamble ack handler 113 of the transmitting node 100 receives the preamble ack from the receiving node 200, the transmitting node 100 knows that the receiving node 200 is currently in the wakeup state, and thus, the preamble ack handler 113 ) Will send the actual data packet. The receiving node 200 waits for a data packet for a predetermined time after transmitting the preamble ack. If it is not received, it abandons the reception and goes back to sleep. If a preamble is received, it retransmits the preamble ack again.

When the receiving node 200 successfully receives the data packet from the transmitting node 100, the packet handler 213 generates and transmits a packet ack.

The transmitting node 100 waits for the data packet ack for a predetermined time after transmitting the data packet, and when the data packet ack is successfully received through the packet ack handler 115, the packet transmission process is completed. If it fails, it retransmits the data packet.

FIG. 5B illustrates a case in which a receiving node temporarily increases a duty cycle for a certain area in which a transmitting node transmits a packet in order to minimize energy consumption of the transmitting node.

If the energy remaining in the battery becomes less than the reference value, the transmitting node 100 notifies the receiving node 200 of the next packet transmission time to reduce the energy consumption of the transmitting node 100 and includes a schedule including the time. During the region, you can ask to increase the duty cycle momentarily.

That is, the preamble ack handler 113 of the transmitting node 100 may generate the data packet by adding the next packet transmission time value and the size of the region when generating the data packet, and includes the next packet transmission time value. The data packet is transmitted to the packet handler 213 of the receiving node 200.

The packet handler 213 of the receiving node 200 receiving the packet checks its battery and memory, and if it can accept this request, it remembers this value and then executes the duty cycle as shown in FIG. Raise it about twice as much. If the request is unacceptable, it is ignored. As such, as the receiving node 200 increases the wake-up duty cycle at a certain instant, the transmitting node 100 may reduce the number of preamble transmissions, thereby minimizing energy consumption.

FIG. 5C illustrates a case in which packet transmission points are delayed by a predetermined time in order to save resources (memory or / and energy) of a receiving node.

The packet handler 213 of the receiving node 200 checks whether the packet transmission can be delayed to the transmitting nodes 100 by a predetermined time according to the margin of the battery and the memory of the receiving node 200.

At this time, the information on the delay time of each transmitting node 100 is determined by the group scheduler 215 of the receiving node 200. The delay time information is included in the packet ack and transmitted to the corresponding transmission node 100. When the transmission node 100 can receive the request according to the delay time condition, the delay time is delayed by that much time to transmit the preamble. do.

For example, in order for the receiving node 200 to receive three data packets from each of the single or plurality of transmitting nodes 100, 15 wakeup periods are required in the case of FIG. 5B. However, as shown in FIG. 5C, as the data packet transmission time is delayed to a specific packet transmission time, the receiving node 200 needs only nine wake-up periods to receive three data packets.

This causes a large number of packet transmissions in a certain section, and the receiving node 200 has advantages such as low data collision probability, fast retransmission, and size reduction of schedule information by increasing the duty cycle for the section.

If the transmitting node 100 cannot receive the request because of the delay time condition, it can simply ignore it. The condition that the receiving node 200 requests the delay transmission may be implemented by various algorithms.

This section describes the simplest algorithm. This is for explanation, and various algorithms are possible depending on the conditions of the delay time.

That is, when a plurality of transmitting nodes 100 are connected to the receiving node 200, the group scheduler 215 of the receiving node 200 has a sliding window whose length is H (determined by the delay time condition D). Window) to store the number of received packets and the transmitting nodes 100. If the number of packets is more than the preset G number, the packet time T last received in the current sliding window is checked, and a delay request is transmitted to the transmitting nodes 100 based on the packet time T last received. do.

The transmitting node 100 uses the delay information that each packet has experienced so far and the number of hops between the transmitting node 100 and the sink node (the number of sensor nodes between the transmitting node and the sink node) and the delay time condition (D). If the condition is satisfied, the request is accepted and the data packet is delayed.

The receiving node 200 increases the duty cycle for a predetermined time after every request of the packet time T after requesting a transmission delay to the transmitting node 100. If the received packet is less than the set G within the predetermined time, the duty cycle is returned to its original state.

As described above, in the present invention, when the transmitting node 100 and the receiving node 200 transmit data, the MAC method as shown in FIGS. 5A, 5B, and 5C is selectively applied or mixed with each other, thereby receiving the transmitting node 100 and the receiving node. The energy consumption of the node 200 can be balanced to maximize the life of the link, thereby maximizing the sensor network life.

의 값에 비례하여 에너지를 소모하기 때문에 에너지 소모를 최소화할 수 있고, 이로 인해 프리앰블 충돌 확률을 낮추어 네트워크의 수명을 최대화할 수 있음과 아울러 신뢰성이 있는 데이터 전송이 가능하게 된다.The existing transmission node 100 consumes energy in proportion to the wakeup period, but the transmission node in the present invention

Since energy is consumed in proportion to the value of, the energy consumption can be minimized. This can reduce the preamble collision probability, thereby maximizing the life of the network and enabling reliable data transmission.

In the present invention, in order to facilitate the implementation of the medium access control protocol, when the duty cycle is high or the inter packet time is short, delay transmission or dynamic duty cycle control may not be performed.

Preferred embodiments of the present invention are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes and additions within the spirit of the present invention. Additions should be considered to be within the scope of the following claims.

1 is a diagram illustrating a general sensor network configuration.

2 is a diagram showing the configuration of a transmitting node and a receiving node of the conventional sensor node, respectively.

3 is a diagram illustrating an example of data transmission between a conventional transmitting node and a receiving node.

4 is a diagram illustrating a configuration of a MAC (Media Access Control) protocol of a transmitting node and a receiving node according to the present invention.

5A to 5C are diagrams for explaining a media access control method according to each embodiment of the present invention.

FIG. 6 is a diagram illustrating a prediction error for calculating a preamble interval in the present invention.

* Explanation of symbols for the main parts of the drawings

100: transmission node (transmission device) 110: transmission module

111: preamble generator 113: preamble ack handler

115: packet ack handler 200: receiving node (receiving device)

210: receiving module 211: preamble handler

213: Packet handler 215: Group scheduler

Claims (8)

A preamble generator for generating a preamble and transmitting the preamble to the receiving device and determining the transmission repetition interval of the preamble by using prediction error information stored in a previous packet transmission; And A preamble ack handler that generates and transmits a data packet when there is an ack (acknowledge) from the corresponding receiver according to the preamble transmission, and requests the receiver to temporarily increase a wake-up duty cycle for a certain time point to transmit the packet if necessary. Transmitter of the sensor network comprising a. The method according to claim 1, The preamble ack handler generates a data packet by adding transmission time information of a next packet when generating a data packet. The method according to claim 1 or 2, The preamble generator is a preamble transmission repetition interval

Is obtained by the following equation, and the preamble transmission repetition interval

To the equation

or

Transmitter of the sensor network, characterized in that determined by the smaller value of the value obtained by. Equation

The method according to claim 1 or 2, The receiver checks its battery and memory in response to a request to increase the wake-up duty cycle of the transmitter and stores this value if it can accept the request. Transmitter of the sensor network, characterized in that the height. A preamble handler which checks whether a preamble having its own destination node always exists in a wake-up state, and generates a preamble ack and transmits the preamble ack to the corresponding transmission apparatus if the preamble exists; A packet handler for receiving a packet transmitted by the transmitting apparatus, generating an ack packet for the transmitting apparatus, and transmitting the generated ack packet to the transmitting apparatus, requesting the transmitting apparatus to delay a preamble transmission time for a predetermined time; And A group scheduler that calculates a data transmission time of each transmitter but calculates a delay time for the data transmission time of each transmitter to provide a packet handler such that the data transmission time of each transmitter is within a predetermined time period; Receiving device on the network. The method according to claim 5, The packet handler checks whether the packet transmission can be delayed to the transmitting apparatuses by a predetermined time according to the amount of battery and memory available, and the information about the delay time of each transmitting apparatus is determined by the group scheduler. The receiving device of the sensor network. The method according to claim 5 or 6, The group scheduler checks the packet time last received from each transmitting device, and determines the delay time of each transmitting device based on the last received packet time. In the sensor network comprising a sensor node and a sink node including a transmitter and a receiver, The transmitting device, A preamble generator for generating a preamble and transmitting the preamble to the receiving device and determining the transmission repetition interval of the preamble by using prediction error information stored in a previous packet transmission; And a preamble ack for generating a data packet when there is an acknowledgment from the corresponding receiver according to the preamble transmission, and if necessary, requesting the receiver to increase a wake-up duty cycle for a predetermined time point for transmitting the packet. A handler; The receiving device, A preamble handler which checks whether a preamble having its own destination node always exists in a wake-up state, and generates a preamble ack and transmits the preamble ack to the corresponding transmission apparatus if the preamble exists; A packet handler for receiving a packet transmitted by the transmitting apparatus, generating an ack packet for the transmitting apparatus, and transmitting the generated ack packet to the transmitting apparatus, requesting the transmitting apparatus to delay a preamble transmission time for a predetermined time; And a group scheduler that calculates a data transmission time point of each transmitting device and calculates a delay time for the data transmission time point of each transmitting device to provide a packet handler so that the data transmission time of each transmitting device is achieved within a predetermined time period. Transmitting and receiving system of the sensor network, characterized in that.

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