KR100952575B1 - Method and apparatus for improving network performance by adjusting bop size in wireless sensor network - Google Patents

Abstract

A method and apparatus for improving network performance through beacon interval size control in a wireless sensor network are disclosed. In the wireless sensor network according to the present invention, a method for improving network performance through beacon interval size adjustment may include adjusting a beacon interval size of a super frame in consideration of the maximum hop size of the wireless sensor network; And applying the adjusted beacon section to the super frame.

Network, Sensor Network, Beacon Section, Hop, Super Frame

Description

METHOD AND APPARATUS FOR IMPROVING NETWORK PERFORMANCE BY ADJUSTING BOP SIZE IN WIRELESS SENSOR NETWORK}

The present invention relates to improving network performance, and more particularly, to a method and apparatus for improving network performance through beacon interval size control in a wireless sensor network.

Wireless Sensor Network (WSN) is a network of distributed sensors spread all over the place. It detects and collects information from specific areas for various applications such as remote monitoring systems, telemedicine and unmanned exploration. A wireless network designed to deliver information to a user through a wireless communication technique.

In wireless sensor networks, sensors can be things like thermometers, hygrometers, cameras or microphones, or sensors that measure things like magnetic fields. It is wireless sensor network that adds wireless network function to these sensors to communicate with each other.

Therefore, the wireless sensor network is responsible for a sensor node that measures and transmits various data over a distributed area, and records and maintains data transmitted from each sensor node, and delivers specific information to a desired user. It consists of a Base Node. The sensor network is also an ad hoc network that enables peer-to-peer communication without the need for a traditional infrastructure.

On the other hand, the wireless sensor network is generally composed of a large number of sensor nodes for the accuracy of sensing and expansion of the sensing area. Therefore, there is a need for a cooperative information transfer system between nodes and a self-organizing ability that can adapt to dynamic situational changes in a large networking environment. In addition, it is necessary to authenticate and protect data transmitted between sensor nodes in order to transmit information detected by various types of sensors to a base node without threat of eavesdropping or forgery. To this end, sensor nodes in the wireless sensor network perform encrypted data communication after performing mutual authentication and security information establishment process.

Nodes constituting a wireless sensor network (WSN) include a destination node, a source node, and an intermediate or relay node according to its function. The destination node is a node to which specific data is to be transmitted as a data receiver, and the source node is a source node of specific data to be transmitted to the destination node as a data transmitter. The relay node refers to nodes constituting a data transmission path from a source node to a destination node.

For example, in a wireless personal area network (WPAN) or wireless sensor network based on IEEE 802.15.4, the system configuration is composed of a data aggregation / fusion destination node and a plurality of data collection sensor nodes. . Each sensor node (mobile or source node) transmits the collected data to the destination node through a process such as path setting.

1 is a diagram illustrating a BOP structure in an IEEE 802.15.4 based WPAN. 2 is a diagram illustrating a network in the form of a chain topology.

As shown in FIG. 1, the Beacon Only Period (BOP) section 110 is set to the number of allowable slots 120, which is approximately 16 in total. The set slot 120 size has a reuse problem when all 16 are used as the number of sensor nodes 210 and 220 increases as shown in FIG. 2.

In addition, there is a large delay in the BOP data transmission (Payload) between the Zigbee Coordinator 210 and the terminal sensor node 220 as the hop increases as in the chain topology of FIG. 2. In addition, there is a problem that a CAP (Contention Access Period) section is wasted due to a relatively large BOP section.

The present invention has been made to improve the prior art as described above, an object of the present invention is to adjust the size of the BOP interval in consideration of the network network structure in the wireless sensor network, it is possible to minimize the packet delay by reusing the beacon interval In addition, the present invention provides a method and apparatus for improving network performance through beacon interval size control in a wireless sensor network.

Another object of the present invention is to provide a method and apparatus for improving network performance through beacon interval size adjustment in a wireless sensor network, which can improve network performance by increasing throughput by repeatedly reusing beacon intervals.

The object of the present invention is not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object and to solve the problems of the prior art, the method for improving network performance by adjusting the beacon interval size in the wireless sensor network according to an embodiment of the present invention, in consideration of the maximum hop size of the wireless sensor network, super frame Adjusting the beacon interval size of the; And applying the adjusted beacon section to the super frame.

The adjusting of the beacon interval size may include: comparing a value obtained by dividing the maximum hop size by a predetermined number with the beacon interval size; And when the beacon section size is larger than the divided value, as a result of the comparison, adjusting the beacon section size to a size corresponding to the predetermined number.

The beacon period includes the allowable number of beacon slots, and the comparing may include comparing the value obtained by dividing the maximum hop size by a predetermined number to the allowable beacon slot number.

The predetermined number may be set in consideration of the physical carrier sensing zone (PCSZ) or the interference range.

The maximum hop size may be set in consideration of the distance between the coordinator and the lighter.

The transmitting may include: reapplying the beacon section by reducing the size of the entire beacon section by overlapping the beacon section having the adjusted size after the hop size corresponding to the predetermined number; And applying the reduced total beacon interval size to the super frame and transmitting the same.

In accordance with an embodiment of the present invention, an apparatus for improving network performance through beacon interval size control in a wireless sensor network includes: an adjusting unit configured to adjust a beacon interval size of a super frame in consideration of the maximum hop size of the wireless sensor network; And a transmitter configured to transmit the beacon interval having the adjusted size to the super frame.

The apparatus for improving network performance through beacon interval size control in a wireless sensor network according to an embodiment of the present invention further includes a comparison unit that compares a value obtained by dividing the maximum hop size by a predetermined number, and comparing the beacon interval size with the adjustment. In the comparison result, when the beacon interval size is larger than the divided value, the beacon interval size may be adjusted to a size corresponding to the selected number.

Specific details of other embodiments are included in the detailed description and the accompanying drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

According to the present invention, by adjusting the size of the BOP interval in consideration of the network structure in the wireless sensor network, it is possible to reuse the beacon interval to minimize the packet delay.

According to the present invention, by repeatedly reuse the beacon interval, it is possible to improve the network performance by increasing the throughput (Throughput).

In the wireless sensor network according to an embodiment of the present invention, a method and apparatus for improving network performance through beacon interval size control efficiently reuses a BOP (Beacon Only Period) interval in an IEEE 802.15.4 based WPAN, thereby delaying packets. Can be minimized and network performance can be improved.

In IEEE 802.15.4 based WPAN, the Physical Carrier Sensing Zone (PCSZ) or Interference Range is typically about twice the transmission range. Therefore, in the chain topology, the BOP section between two adjacent sensor nodes can be set to PCSZ up to 4 hops when one hop distance is 20m. After the PCSZ, the BOP slot interval may be reused provided that there is no interference with each other.

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

3 is a flowchart illustrating a method for improving network performance through beacon interval size control in a wireless sensor network according to an embodiment of the present invention. Here, the network performance improving method may be implemented by a network performance improving apparatus mounted in the network coordinator. The network coordinator will be described herein as limited to the Zigbee Coordinator. However, limiting the network coordinator to the ZigBee coordinator is for convenience of description and understanding of the present invention, and is not intended to narrow the scope of implementation of the invention.

Referring to FIG. 3, in step S310, the Zigbee coordinator compares a value obtained by dividing the maximum hop size (Max_Hop_Count) of the wireless network by a predetermined number, and the beacon interval size (BOP_length) of the super frame. Here, the maximum hop size may be set in consideration of the distance between the Zigbee coordinator and the Zigbee lighter. That is, since the Zigbee coordinator can know the distance according to the number of hops, the maximum hop size can be obtained in consideration of the distance to the Zigbee lighter.

In addition, the beacon interval (BOP) includes an allowable number of beacon slots, and the predetermined number may be set in consideration of a physical carrier sensing zone (PCSZ) or an interference range.

For example, the beacon section may include 16 slots. The selected number may be set to 4 hop counts. This is because, as described above, when one hop distance is 20m, up to four hops can be taken as PCSZ.

As a result of the comparison, when the beacon interval size is larger than a value obtained by dividing the maximum hop size Max_Hop_Count by a predetermined number, step S320 is performed.

That is, in step S320, the Zigbee coordinator adjusts the beacon interval size BOP_length. In this case, the Zigbee coordinator may adjust the size of the beacon section to a size corresponding to the selected number.

As described above, the Zigbee coordinator may adjust the size of the beacon interval of the super frame in consideration of the maximum hop size of the wireless sensor network.

Next, in step S330, the Zigbee coordinator transmits the beacon interval of the adjusted size to the super frame. That is, the Zigbee coordinator may overlap the beacon section of the adjusted size after the hop size corresponding to the selected number by overlapping the beacon section to reduce the size of the entire beacon section by reusing the beacon section. The beacon interval size may be applied to the super frame and transmitted.

For example, the Zigbee coordinator may reduce the size of the entire beacon section by reusing the beacon section by overlapping the beacon section adjusted to the size of 4 hops after 5 hops.

As described above, the Zigbee coordinator adjusts the size of the beacon interval of the super frame in consideration of the maximum hop size of the wireless sensor network, and reuses the size of the adjusted beacon interval in duplicate, thereby reducing packet delay and utilization rate. You can increase the throughput. That is, the network performance can be improved.

On the other hand, if the comparison result, the beacon interval size is less than or equal to the value of the maximum hop size (Max_Hop_Count) divided by the predetermined number, the Zigbee coordinator maintains the beacon interval size in step (S340). In operation S350, the Zigbee coordinator transmits the beacon interval of the maintained size to the super frame.

4 is a diagram illustrating an example of a chain topology structure applied to an embodiment of the present invention.

Hereinafter, referring to FIG. 4, Table 1 and Table 2, the network performance according to the BOP usage when the network structure is not considered and the network performance according to the case of resetting the BOP interval size in consideration of the network structure are compared. Will be explained.

As shown in FIG. 4, the network topology has a chain topology, and the maximum hop size Max_Hop_Count is 30 hops.

First, when the network structure is not considered, the size of the BOP interval is 16 x BOP_Slot (5m) = 80msec as shown in Table 1 below. Accordingly, the occupancy rate of the BOP section in the CAP section is 8/400 = 2%, and the maximum BOP payload latency is 16 x 5 = 80 msec.

As such, when the network structure is not considered, network performance due to the use of BOP is not efficient.

On the other hand, when considering the network structure, the size of the BOP interval is 4 x BOP_Slot (5m) = 20msec as shown in Table 2 below. Accordingly, the occupancy rate of the BOP section in the Contention Access Period (CAP) section is 2/400 = 0.5%, and the maximum BOP Payload Latency is 4 x 5 = 20 msec.

As such, when the BOP interval size is reconfigured in consideration of the network structure, network performance may be improved by reducing packet delay and increasing throughput.

In the wireless sensor network according to an embodiment of the present invention, the method for improving network performance by adjusting the beacon interval size includes a computer readable medium including program instructions for performing operations implemented by various computers. The computer readable medium may include program instructions, local data files, local data structures, or the like, alone or in combination. The media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical recording media such as CD-ROMs, DVDs, magnetic-optical media such as floppy disks, and ROM, RAM, flash memory, and the like. Hardware devices specifically configured to store and execute the same program instructions are included. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

5 is a block diagram illustrating an apparatus for improving network performance through beacon interval size control in a wireless sensor network according to an embodiment of the present invention. Here, the network performance improving apparatus may be mounted in the Zigbee coordinator as described above.

Referring to FIG. 5, the apparatus for improving network performance may include a comparator 510, an adjuster 520, a transmitter 530, and a controller 540.

The comparator 510 compares a value obtained by dividing the maximum hop size Max_Hop_Count of the network by a predetermined number with a beacon interval size BOP_length of the super frame. Here, the maximum hop size may be set in consideration of the distance between the Zigbee coordinator and the Zigbee lighter. In addition, the beacon interval (BOP) includes an allowable number of beacon slots, and the predetermined number may be set in consideration of a physical carrier sensing zone (PCSZ) or an interference range.

The adjusting unit 520 may adjust the size of the beacon section according to the comparison result. That is, when the beacon interval size is greater than the value obtained by dividing the maximum hop size Max_Hop_Count by a predetermined number, the control unit 520 may have a size corresponding to the beacon interval size BOP_length corresponding to the selected number. Adjust the beacon section size.

The transmitter 530 applies the beacon section of the adjusted size to the super frame and transmits it. That is, the transmitter 530 may reduce the size of the entire beacon section by reusing the beacon section by overlapping the beacon section having the adjusted size after the hop size corresponding to the selected number. The entire beacon interval size can be applied to the super frame and transmitted.

The controller 540 may control operations of the comparator 510, the controller 520, and the transmitter 530.

As described above, the apparatus for improving network performance adjusts the beacon interval size of the super frame in consideration of the maximum hop size of the wireless sensor network, and reuses the size of the adjusted beacon interval by overlapping the packet delay. Reduce throughput and increase throughput. That is, the network performance can be improved.

While specific embodiments of the present invention have been described so far, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below, but also by the equivalents of the claims.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Modifications are possible. Accordingly, the spirit of the present invention should be understood only by the claims set forth below, and all equivalent or equivalent modifications thereof will belong to the scope of the present invention.

1 is a diagram illustrating a BOP structure in an IEEE 802.15.4 based WPAN.

FIG. 2 is a diagram illustrating a network in the form of a chain topology.

3 is a flowchart illustrating a method for improving network performance through beacon interval size control in a wireless sensor network according to an embodiment of the present invention.

4 is a diagram illustrating an example of a chain topology structure applied to an embodiment of the present invention.

5 is a block diagram illustrating an apparatus for improving network performance through beacon interval size control in a wireless sensor network according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

110: beacon section 120: beacon slot

210: coordinator 220: sensor node

510: comparison unit 520: control unit

530: transmission unit 540: control unit

Claims (9)

In the method of improving network performance in a wireless sensor network, Comparing the value obtained by dividing the maximum hop size of the wireless sensor network by a predetermined number with a beacon interval size of a super frame; As a result of the comparison, if the beacon interval size is larger than the divided value, adjusting the beacon interval size to a size corresponding to the predetermined number; And Transmitting a beacon section of the adjusted size to the super frame Method for improving network performance by adjusting the beacon interval size in a wireless sensor network comprising a. delete The method of claim 1, The beacon section includes an allowable number of beacon slots, Comparing the divided value with the beacon interval size of the super frame, Comparing the maximum hop size divided by a predetermined number with the allowable beacon slot number Method for improving network performance by adjusting the beacon interval size in a wireless sensor network comprising a. The method of claim 1, The selected number is A method for improving network performance by adjusting beacon interval size in a wireless sensor network, characterized in that set in consideration of a physical carrier sensing zone (PCSZ) or an interference range. The method of claim 1, The maximum hop size is, Method for improving network performance by adjusting the beacon interval size in the wireless sensor network, characterized in that set in consideration of the distance between the coordinator and the lighter. The method of claim 1, The step of transmitting the adjusted beacon interval of the size to the super frame, Reducing the size of the entire beacon section by reusing the beacon section by overlapping the beacon section having the adjusted size after the hop size corresponding to the predetermined number; And Transmitting the reduced total beacon interval size to the super frame Method for improving network performance by adjusting the beacon interval size in a wireless sensor network comprising a. A computer-readable recording medium for recording a program for executing the method of any one of claims 1 and 3 to a computer. An apparatus for improving network performance in a wireless sensor network, A comparison unit which compares a value obtained by dividing the maximum hop size of the wireless sensor network by a predetermined number, with a beacon interval size of a super frame; The comparison result, if the beacon interval size is larger than the divided value, adjusting the beacon interval size to a size corresponding to the predetermined number; And Transmitter for transmitting the beacon interval of the adjusted size to the super frame Apparatus for improving network performance through beacon interval size control in a wireless sensor network comprising a. The method of claim 8, The transmission unit, By repeatedly applying the adjusted beacon section after the hop size corresponding to the predetermined number, the beacon section is reused to reduce the overall beacon section size, and the reduced total beacon section size is the super frame. Apparatus for improving network performance by adjusting the beacon interval size in the wireless sensor network characterized in that the transmission to apply.

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