KR101269234B1 - Method and apparatus transmitting data based on link quality in wireless network - Google Patents

Abstract

PURPOSE: A link quality based data transmission method in a wireless network and a device thereof are provided to transmit data by selecting a transmission path including the link quality which is over a threshold value. CONSTITUTION: A link quality measuring unit(613) receives a transmitted control packet. The link quality measuring unit measures the link quality for a link of a node transmitting the control packet. A path cost calculation unit(614) calculates the path costs based on the measured link quality. A flag setting unit(615) sets a flag by comparing a threshold value with the calculated path costs. A storage unit(616) stores a routing table including the set flag. [Reference numerals] (610) Routing table establishment unit; (611) Node initialization unit; (612) Control packet transmission unit; (613) Link quality measurement unit; (614) Path cost calculation unit; (615) Flag setting unit; (616) Storage unit; (620) Data packet transmission unit; (621) Transmission path determination unit; (622) Transmission unit

Description

Method and apparatus for transmitting data based on link quality in wireless network {method and apparatus transmitting data based on link quality in wireless network}

The present invention relates to a data transmission method in a wireless network, and more particularly, to a technique for selecting a path and transmitting data based on link quality in a wireless network. The present invention relates to a link quality based routing method in a mobile adhoc network (WSN) or a wireless sensor network (WSN).

The wireless network performs a route setting step to select a path to transmit data, and the mobile ad hoc network (MANET) selects a control message RREP (Route) that the destination node responds to a control message RREQ (Route Request) broadcast from the source node. End-to-end path is selected through the path of Reply).

Meanwhile, in the wireless sensor network WSN, a sensor node selects a path based on a control message broadcast from a sink node.

The conventional wireless network path selection method selects a path based on the hop count of a broadcast control message.

However, a path having poor link quality between nodes may be selected as a transmission path having the shortest end-to-end hop.

This poor link quality can cause frequent transmission failures during data transmission, resulting in increased transmission delays due to retransmissions, resulting in increased energy consumption of nodes.

Therefore, when selecting a transmission path in order to increase transmission reliability in a wireless network, a transmission path selection method and a data transmission method in consideration of link quality need to be proposed.

The present invention, in order to solve the above-mentioned problems of the prior art, predicts the link quality of the end-to-end path using the average deviation of the link quality, and selects a transmission path from the link having a link quality of more than a threshold value to transmit data And an apparatus.

One embodiment of the present invention for achieving the technical problem of the present invention, in the link quality-based data transmission method in a wireless network, routing for setting information on the transmission path based on the link quality based on the control packet on the wireless network Table construction step; And a data packet transmission step of selecting a transmission path of a data packet to be transmitted from a source node using the constructed routing table and transmitting the data packet to a destination node through the selected path.

The establishing of the routing table may include: initializing a node by setting a threshold value (Wth) of link quality, which is a criterion for path selection; Transmitting a control packet including a routing control message for establishing the routing table; Measuring a link quality for a link of a node receiving the transmitted control packet and transmitting the control packet; Calculating a path cost based on the measured link quality; Setting a flag by comparing the calculated path cost with the threshold value Wth; And storing a routing table including the set flag.

In the step of transmitting the control packet, it is preferable to piggyback and broadcast the link quality information measured at the current node to calculate the path cost on the n + 1th link after the current nth link.

The measuring of the link quality may further include measuring a received signal strength indicator (RSSI) or a link quality indicator (LQI) value when the control packet is received by the wireless module of the current node and recording the same in the routing table. It is desirable to.

The calculating of the path cost may include: initial link quality (L1), sum of link quality deviations (Di-1), link quality information (Li-1) of a previous node, and transmission from the received control packet Extracting the hop number (H); The measured link quality of the current node along with the extracted initial link quality (L1), sum of link quality deviations (Di-1), link quality information (Li-1) of previous nodes and transmitted hop count (H) Calculating a route cost (W) using Li); And recording the calculated path cost (W) in a routing table.

의 방식으로 계산되는 것이 바람직하다.The step of calculating the path cost is calculated using the quality of the original link and the average link quality deviation for multi-hop transmission,

It is preferably calculated in the manner of.

In setting the flag in comparison with the threshold value, it is preferable to set a flag in an entry of a routing table having a value corresponding to the threshold value or less of the calculated path cost.

Resending the control packet after storing the routing table, wherein the resending includes: a sum Di of link quality deviation, which is piggyback information of the control packet, and link quality information of a previous node ( It is desirable to update Li-1) and the transmitted hop number H to broadcast to neighbor nodes.

The transmitting of the data packet further includes determining a transmission path of the data packet, and determining the transmission path includes determining a transmission path between at least one link having a link quality value greater than the threshold. It is desirable to.

The determining of the transmission path may include selecting a path having a shortest hop count among at least one or more paths in which no flag included in the entry is set among the entries in the routing table, and determining the transmission path as the transmission path. desirable.

On the other hand, another embodiment of the present invention for achieving the technical problem of the present invention, in the link quality-based data transmission apparatus in a wireless network, using the control packet on the wireless network to set the information on the transmission path based on the link quality A routing table constructing unit; And a data packet transmitter configured to select a transmission path of a data packet to be transmitted from a source node using the constructed routing table and to transmit the data packet to a destination node through the selected path.

The routing table building unit may include: a node initialization unit configured to set a threshold value Wth of a link quality that is a criterion for path selection; A control packet transmitter for transmitting a control packet including a routing control message for establishing the routing table; A link quality measuring unit which receives the transmitted control packet and measures a link quality of a link of a node that has transmitted the control packet; A path cost calculator configured to calculate a path cost based on the measured link quality; A flag setting unit for setting a flag by comparing the calculated path cost with the threshold value Wth; And a storage unit which stores a routing table including the set flag.

The data packet transmitter may include a transmission path determiner configured to determine a transmission path of the data packet; And a transmitter configured to transmit the data packet through the determined transmission path, wherein the transmission path determiner determines a transmission path between at least one or more links having a link quality value larger than the threshold.

Meanwhile, another embodiment of the present invention for achieving the technical problem of the present invention is end-to-end through the path of the second control message that the destination node responds to the first control message broadcast from the source node of the wireless network Estimating a link quality of the end-to-end path using an average deviation of link quality between each node of the wireless network in selecting a path; Comparing the predicted link quality with a predetermined threshold indicating a reliability of a radio link and selecting a path having a link quality greater than the threshold as a transmission path; And transmitting a data packet through the selected transmission path.

According to the link quality-based data transmission method and apparatus according to the present invention, the following effects can be obtained by performing link quality-based path selection and transmitting data packets in a wireless network.

First, data packets can be transmitted by avoiding lossy paths by ensuring link quality above a given threshold (Wth).

Second, the number of retransmissions for the lost packet can be reduced by selecting a path having a high transmission reliability of the link and transmitting the data packet.

Third, it is possible to reduce the energy consumption of each node constituting the wireless network, and to extend the life of the entire network.

1 is a flowchart showing the overall flow according to an embodiment of the present invention.
2 is a flowchart showing in detail a method for constructing a routing table entry for transmission path selection according to an embodiment of the present invention.
3 is a flowchart illustrating a method of selecting a transmission path for transmitting a data packet and transmitting the packet using a routing table constructed according to an embodiment of the present invention.
4 is a table entry structure diagram for describing field information of a routing table constructed according to an embodiment of the present invention.
5 is a conceptual diagram illustrating an exemplary scenario of a link quality based data transmission method in a wireless network according to an embodiment of the present invention.
6 is a functional block diagram illustrating an apparatus for transmitting link quality based data in a wireless network according to another embodiment of the present invention.

Hereinafter, 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. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same or similar parts are designated by the same or similar reference numerals throughout the specification.

Throughout this specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding the other components unless otherwise stated.

In addition, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

The present invention provides a path selection method performed in a mobile ad hoc network (MANET) or a wireless sensor network (WSN) and a data transmission method using the same, including: initializing a node, transmitting a routing control message to establish a routing table, and routing Receiving a control message to measure the quality of the link; constructing a routing table by calculating the route cost based on the piggyback information and the measured link quality information of the received message; And setting a flag by comparing a to a threshold (threshold), determining a path between links having a value greater than or equal to the threshold, and transmitting a data packet along the determined path.

Looking at each of the above-mentioned steps in detail, the step of initializing the node includes the step of setting the threshold (Wth) of the link quality required for the path selection. In the present invention, a transmission path of a data packet is selected between links having a link quality equal to or higher than the link quality threshold Wth set as described above.

Transmitting the routing control message then includes piggybacking and broadcasting the link quality information measured at the current node for calculating the path cost on the next link.

In addition, the measuring of the link quality of the control message may include measuring a received signal strength indicator (RSSI) or a link quality indicator (LQI) value in the routing table when the RF module receives the packet.

Computing the path cost may include extracting piggybacked information (eg, sum L of link quality, link quality deviation D, link quality information Li-1 of previous node, and transmission hop number H) from the received packet. And calculating the route cost Wi by using the extracted information and the measured link quality information, and displaying the calculated route cost in the routing table.

At this time, the routing control message is broadcast to establish a routing path, and another node receiving the routing control message retransmits (ie, re-broadcasts) the routing control message after calculating the route cost for the route selection.

Comparing the calculated path cost and the threshold includes setting a flag in a routing table entry having a value corresponding to a threshold Wth or less of the calculated path costs in the routing table.

The determining of the transmission path includes selecting a path having the shortest hop among the paths that are not flagged among entries in the routing table.

At this time, the threshold (Wth) is a measure of radio link reliability. For transmission considering the link quality, it is necessary to select a path having a link quality above this threshold (Wth). desirable.

Finally, transmitting the data packet includes transmitting the data packet using a transmission path selected through the path determination step.

The above is a schematic configuration step of a path selection technique performed in a mobile ad hoc network (MANET) or a wireless sensor network (WSN) and a data transmission method using the same. Referring to the accompanying drawings, the present invention will be described in more detail below. Explain.

1 is a flowchart showing the overall flow according to an embodiment of the present invention.

A link quality based data transmission method in a wireless network can be largely composed of two steps. One is a routing table establishment step of setting information on a transmission path based on link quality using control packets on a wireless network. The other is a data packet transmission step of selecting a transmission path of a data packet to be transmitted from a source node using the thus constructed routing table, and transmitting the data packet to a destination node through the transmission path.

In other words, in the wireless network, in particular, the mobile ad hoc network (MANET) and the wireless sensor network (WSN), a procedure for establishing a routing table for setting information on the transmission path by the control packet generated as shown in FIG. And a process of selecting a path through a routing table and transmitting a data packet (ie, a process including steps 150 and 160) for data packet transmission.

Referring to each step with reference to FIG. 1, first, a packet is generated from an application service or a packet sent from another node is generated (110), and it is determined whether it is a control packet for path setting according to the type of the generated packet (120). ).

If the control packet is received, a link quality based routing table setting step 130 is performed, and the control packet for path establishment is retransmitted (ie, re-broadcasted) (140).

If a data packet is generated, after selecting a transmission path by searching a routing table constructed based on link quality (150), the data packet is transmitted to the selected path (160).

Here, the link quality-based routing table setting step will be described in more detail below, initializing a node for setting a threshold (Wth), measuring a link quality, extracting information of the received control packet, path Calculating a cost, setting a flag by comparing the path cost with a threshold Wth, and storing a routing table entry containing the set flag.

Hereinafter, the two large processes constituting the present invention, which are a transmission path selection method and a data transmission method in consideration of link quality, will be described.

That is, the procedures 130 and 140 for establishing a routing table for setting information on the transmission path by the control packet, and a procedure for selecting a transmission path and transmitting the data packet through the already established routing table for data packet transmission ( 150 and 160 will be divided and described in detail.

2 is a flowchart showing in detail a method for constructing a routing table entry for transmission path selection according to an embodiment of the present invention.

The routing table building step may include: initializing the node by setting a threshold value Wth, which is a criterion for path selection, 210, and transmitting a control packet including a routing control message for establishing a routing table ( 220, measuring the link quality for the link of the node receiving the transmitted control packet and transmitting the control packet 230, calculating the path cost based on the measured link quality 240, the calculated Comparing a path cost with the threshold value Wth to set a flag 250 and storing a route table 260 including the set flag.

Looking at each step in detail, first each node performs a node initialization step of setting the threshold (Wth) (210), and transmits a control packet to build a routing table (220).

At this time, in step 220 of transmitting the control packet, the link quality information measured at the current node is piggybacked and broadcasted to calculate the path cost on the next link of the current link.

Subsequently, when receiving a control packet transmitted from another node, the link quality of the link of the node that transmits the control packet is measured (230). At this time, RSSI (Received) indicating the link quality of the link of the node of the node transmitting the control packet is received. Signal strength indicator (LQI) or link quality indicator (LQI) information may be measured and recorded in the routing table.

After performing the link quality measurement step 230, the step of extracting piggyback information included in the control packet may be further performed.

The control packet is transmitted by piggybacking the original link quality (L1), the sum of the link quality deviations (Di-1), the link quality information (Li-1) of the previous node, and the number of transmitted hops (H). In the step of extracting piggyback information, the information on the quality of the first link (L1), the sum of the link quality deviations (Di-1), the link quality (Li-1) of the previous node, and the number of transmission hops (H) are extracted. do.

And the current measured previously with the extracted information (i.e. original link quality (L1), sum of link quality deviations (Di-1), link quality information of previous node (Li-1) and transmitted hops (H)) The path cost W may be calculated using the link quality Li of the node, and the calculated path cost Wi may be recorded in the routing table.

Based on the extracted information, routing table entries are set through the path cost calculation and routing table writing steps.

The path cost to the destination uses the average link quality deviation for the initial link quality and multi-hop transmission, and the path cost can be calculated as in Equation 1 below.

The calculated path cost (W), the number of transmission hops (h), and the measured link quality (li) can be recorded in the routing table along with the destination address and the next hop address of the reverse path.

The path cost calculated in the routing table (W) is compared with the threshold value Wth set in the step of comparing the path cost and the threshold value Wth, and the path cost W corresponding to the threshold value Wth or less of the calculated path costs. The flag may be separately recorded in the routing entry having the Rx and the routing entry having the path cost W larger than the threshold Wth.

For example, if a flag is set to FALSE in a routing entry with a path cost W that is less than or equal to the threshold Wth, a routing entry with a path cost W that is greater than the threshold Wth may be flagged. Can be set to TRUE.

On the other hand, after storing the routing table may include the step of retransmitting (re-broadcast) the control packet, in the control packet re-broadcasting step to update the information of the received control packet to the neighbor node Broadcast again.

Accordingly, the update of the control packet at the node i may include a sum update of the link quality deviation Di, a link quality Li-1 update of the previous node, and a hop number H update step.

The update of the control packet uses routing entry information having the shortest hop among the routing entries whose path cost W is greater than the threshold Wth.

Among routing entries having the same hop, the control packet is updated using routing entry information having a high path cost (W).

The sum Di of the link quality deviation is the sum of the link quality deviation Di-1 of the received control packet and the previous node link quality Li-1 of the received control packet and the control packet when Equation 2 below is used. Calculate through the measured link quality (Li) and update the control packet.

In the previous node link quality update step, the control packet is updated with the value of the link quality field of the routing entry having the highest path cost (W).

In the hop number update step, the control packet is updated to a value in which the hop number of the routing entry having the highest path cost (W) is increased by +1.

When the control packet is updated in this way, a rebroadcast is performed to the neighbor node. The neighbor node receiving the re-broadcasted control packet repeats the above steps to perform routing table entry setting.

3 is a flowchart illustrating a method of selecting a transmission path for transmitting a data packet and transmitting the packet using a routing table constructed according to an embodiment of the present invention.

That is, a procedure of transmitting a data packet using the routing table entry constructed in FIG. 2 described above is described.

The data packet transmission procedure includes retrieving the established routing table entry (310), selecting a path with no flag set (320), selecting a path with the shortest hop value (330), and selecting the selected path. Step 340 of transmitting the data packet.

In the step 310 of retrieving a routing entry, when a data packet for transmission occurs, the route table is searched for a route to a destination.

In this case, since a routing entry in which a flag is set in the routing table means a link quality of less than or equal to the threshold Wth, in this case, since transmission reliability cannot be guaranteed, it is excluded from the path selection.

In step 330 of selecting a path having the shortest hop value, a routing entry having the shortest hop is selected as a transmission path among routing entries for which a flag is not set in the routing table.

In step 340 of transmitting the data packet, the data packet is transmitted using a transmission path having the predetermined shortest hop value.

4 is a table entry structure diagram for describing field information of a routing table constructed according to an embodiment of the present invention.

2 illustrates an entry structure of a routing table utilized in the flowcharts of FIGS. 2 and 3.

The routing table consists of a destination address field, a next hop address field, a hop count field, a path cost field, a link quality field, and a flag field.

When setting each path, a routing table entry including a field as shown in FIG. 4 is constructed, and when a data packet is transmitted, a path is selected by referring to the constructed routing table.

5 is a conceptual diagram illustrating an exemplary scenario of a link quality based data transmission method in a wireless network according to an embodiment of the present invention.

First, an example of a link quality based routing scheme in a mobile ad hoc network (MANET) is shown.

In FIG. 5, the source node N1 performs a path search to transmit data to the destination node N3. The path search is performed through exchange of a Route Request (RREQ) and a Route Reply (RREP) packet.

When the source node N1 broadcasts the RREQ including the piggyback information, the node receiving the RREQ establishes a routing table for a reverse route to the source node N1.

After building the routing table, the relay node rebroadcasts the RREQ again.

The destination node N3 selects a path having the shortest hop among the routing entries having a path cost W greater than the threshold Wth in the routing table for the reverse path, and sends the RREP to the source node N1.

As the RREP packet is relayed to the source node N1, at the relay node, the path to the destination node N3 is set as an entry in the routing table.

The source node N1 receiving the RREP may transmit a data packet using a path to the destination node N3 set in the routing table.

Meanwhile, the wireless sensor network WSN can transmit data packets in the same manner as the mobile ad hoc network MANET.

In the wireless sensor network WSN, a path from the sensor node to the base station SINK is set in the routing table through a control packet broadcast from the base station SINK.

The control packet received from the base station provides a path based on the link quality of the sensor node toward the base station SINK using the routing table building method illustrated in FIG. 2.

The sensor node transmits the data packet to the base station SINK using the path selection method shown in FIG.

As described above, the present invention excludes a path whose link quality is less than or equal to the threshold Wth from the path selection so that data packets are transmitted through a path having high link reliability.

If the conventional technology for routing a wireless network uses only the hop number, the data packet will be transmitted using the path of N1-N2-N3 in the example of FIG. 5 above.

However, since the paths of N1-N2-N3 include paths with low link reliability (N2-N3), frequent packet loss and subsequent retransmission may occur.

Packet loss and retransmission cause loss of data at the destination, delay in transmission, and high energy consumption due to frequent wireless communication by retransmission in the overall network performance.

Therefore, according to the present invention, by selecting a path having a predetermined level or more as a link path, the reliability of data transmission can be increased, and the energy consumed for data packet transmission can be minimized by reducing retransmission due to packet loss.

6 is a functional block diagram illustrating an apparatus for transmitting link quality based data in a wireless network according to another embodiment of the present invention.

Referring to FIG. 6, a link quality based data transmission apparatus in a wireless network may include a routing table constructing unit 610 for setting information on a transmission path based on link quality using a control packet on a wireless network, and a constructed routing table. The data packet transmission unit 620 selects a transmission path of a data packet to be transmitted from a source node and transmits the data packet to a destination node through the selected path.

More specifically, the routing table building unit 610 may include a node initialization unit 611 for setting a threshold Wth of link quality as a reference for selecting a path, and a control packet including a routing control message for establishing a routing table. A control packet transmitter 612 for transmitting a packet, a link quality measurement unit 613 for receiving a transmitted control packet and measuring a link quality of a link of a node that has transmitted the control packet, and based on the measured link quality A path cost calculation unit 614 for calculating a cost, a flag setting unit 615 for setting a flag by comparing the calculated path cost with the threshold value Wth, and a storage unit for storing a routing table including the set flag ( 616).

The data packet transmitter 620 may further include a transmission path determiner 621 for determining a transmission path of the data packet and a transmitter 622 for transmitting the data packet through the determined transmission path. The transmission path determining unit 621 may determine a transmission path between at least one or more links having a value equal to or greater than a threshold.

In short, if the conceptual concept of link quality-based data transmission according to the present invention is largely divided, the terminal may be terminated through a path of a second control message in which a destination node responds to a first control message broadcast from a source node of a wireless network. Estimating the link quality of the end-to-end path using an average deviation of link quality between nodes of the wireless network when selecting an inter-path, and calculating a threshold value (Wth) representing reliability of the radio link and predicted link quality. In comparison, it can be said that it consists of selecting a path having a link quality larger than a threshold as a transmission path, and transmitting a data packet through the selected transmission path.

By selecting the transmission path based on the link quality and transmitting the data packet in the wireless network, it is possible to guarantee the link quality over a predetermined threshold (Wth), to avoid the lossy path, and to transmit the link with high reliability. By selecting a path and transmitting data packets, the number of retransmissions for lost packets can be reduced. In addition, the effect of reducing the energy consumption of the wireless network nodes, it is possible to extend the life of the entire network.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. Codes and code segments constituting the computer program may be easily inferred by those skilled in the art. Such a computer program may be stored in a computer-readable storage medium and read and executed by a computer, thereby implementing embodiments of the present invention. As a storage medium of the computer program, a magnetic recording medium, an optical recording medium, or the like can be included.

It is also to be understood that the terms such as " comprises, "" comprising," or "having ", as used herein, mean that a component can be implanted unless specifically stated to the contrary. But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (14)

In the link quality-based data transmission method in a wireless network,
A routing table establishment step of setting information on a link quality based transmission path using a control packet on a wireless network; And
A data packet transmission step of selecting a transmission path of a data packet to be transmitted from a source node using the constructed routing table and transmitting the data packet to a destination node through the selected path;
The routing table building step,
Initializing a node by setting a threshold value Wth of link quality as a criterion for path selection;
Transmitting a control packet including a routing control message for establishing the routing table;
Measuring a link quality for a link of a node receiving the transmitted control packet and transmitting the control packet;
Calculating a path cost based on the measured link quality;
Setting a flag by comparing the calculated path cost with the threshold value Wth; And
And storing a routing table including the set flag.
delete The method of claim 1,
The step of transmitting the control packet,
Link quality-based data transmission method characterized by piggybacking and broadcasting the link quality information measured at the current node to calculate the path cost on the n + 1 th link following the current n th link.
The method of claim 3,
Measuring the link quality,
When the control module receives the control packet at the current node, the method further includes measuring a received signal strength indicator (RSSI) or a link quality indicator (LQI) value and recording the same in the routing table. Data transfer method.
5. The method of claim 4,
Computing the route cost,
Extracting first link quality (L1), sum of link quality deviation (Di-1), link quality information (Li-1) of previous node, and transmitted hop number (H), which are piggyback information, from the received control packet ;
The measured link quality of the current node along with the extracted initial link quality (L1), sum of link quality deviations (Di-1), link quality information (Li-1) of previous nodes and transmitted hop count (H) Calculating a route cost (W) using Li); And
And recording the calculated path cost (W) in a routing table.
The method of claim 5,
Computing the route cost,
Calculated using the quality of the original link and the average link quality deviation for multi-hop transmission,

Link quality-based data transmission method, characterized in that calculated by the formula.
The method according to claim 6,
Setting a flag in comparison with the threshold value,
And linking an entry of a routing table having a value equal to or less than the threshold value among the calculated path costs.
The method of claim 7, wherein
Retransmitting the control packet after storing the routing table;
The retransmitting may include updating the sum of the link quality deviation Di, which is piggyback information of the control packet, the link quality information Li-1 of the previous node, and the number of transmitted hops H to broadcast to the neighbor node. Link quality based data transmission method, characterized in that.
The method of claim 1,
The transmitting of the data packet further includes determining a transmission path of the data packet.
The determining of the transmission path may include determining a transmission path between at least one or more links having a link quality value larger than the threshold.
10. The method of claim 9,
Determining the transmission path,
Link quality-based data transmission, characterized in that the transmission path is selected by selecting a path having the shortest hop count among at least one or more paths in which the flag included in the entry is not set among the entries in the routing table. Way.
An apparatus for transmitting data based on link quality in a wireless network,
A routing table constructing unit for setting information on a link quality based transmission path using a control packet on a wireless network; And
A data packet transmitter configured to select a transmission path of a data packet to be transmitted from a source node using the constructed routing table and to transmit the data packet to a destination node through the selected path;
The routing table building unit,
A node initializer configured to set a threshold value Wth of a link quality as a criterion for path selection;
A control packet transmitter for transmitting a control packet including a routing control message for establishing the routing table;
A link quality measuring unit which receives the transmitted control packet and measures a link quality of a link of a node that has transmitted the control packet;
A path cost calculator configured to calculate a path cost based on the measured link quality;
A flag setting unit for setting a flag by comparing the calculated path cost with the threshold value Wth; And
And a storage unit for storing a routing table including the set flag.
delete The method of claim 11,
The data packet transmission unit,
A transmission path determining unit determining a transmission path of the data packet; And
And a transmitter configured to transmit the data packet through the determined transmission path.
The transmission path determining unit determines the transmission path between at least one or more links having a link quality value larger than the threshold value.
In selecting the end-to-end path through the path of the second control message to which the destination node responds to the first control message broadcast from the source node of the wireless network, the average deviation of link quality between each node of the wireless network is determined. Predicting the link quality of the end-to-end path using;
Comparing the predicted link quality with a predetermined threshold indicating a reliability of a radio link and selecting a path having a link quality greater than the threshold as a transmission path; And
Link quality-based data transmission method comprising the step of transmitting a data packet through the selected transmission path.

Images