KR101278730B1 - Method, device and computer-readable recording medium for avoiding frequency interference of binary cdma communication - Google Patents

Abstract

PURPOSE: A frequency interference avoidance method of binary CDMA (Code Division Multiple Access) communication, a device, and a computer readable recording medium are provided to minimize frequency interference between Wi-Fi and Zigbee communication by executing binary CDMA communication. CONSTITUTION: A communication unit (110) sets up a pico-net value. The communication unit transmits a beacon to a slave unit. The communication unit receives a synchronization request signal from the slave unit. The communication unit transmits data to the slave unit and receives the data from the slave unit. A first wireless reception sensitivity determination unit (130) periodically inspects the slave unit and data reception sensitivity in a data transmission and reception process. When the slave unit which has under reference sensitivity is over reference rates, the first wireless reception sensitivity determination unit disconnects synchronization with all slave units. [Reference numerals] (100) Channel search unit; (110) Communication unit; (120) Communication connection allowance unit; (130) First wireless reception sensitivity determination unit; (150) Control unit

Description

METHOD, DEVICE AND COMPUTER-READABLE RECORDING MEDIUM FOR AVOIDING FREQUENCY INTERFERENCE OF BINARY CDMA COMMUNICATION}

The present invention provides a method, apparatus, and a computer for frequency interference avoidance of binary CDMA communication, which minimizes frequency interference with Wi-Fi or Zigbee, which share a 2.4 GHz band in performing binary CDMA communication. A readable recording medium.

More specifically, the present invention searches for an idle channel in performing binary CDMA communication, performs communication using the corresponding channel, and grasps the reception sensitivity in real time while performing communication to preempt the optimal channel to a high level of communication quality. A method and apparatus for avoiding frequency interference in binary CDMA communication, and a computer-readable recording medium, which can be maintained in the same manner.

Recently, with the emergence of smart grid technology, research on the field of intelligent remote meter reading is being actively conducted. Accordingly, the development of low cost, high performance remote metering technology has become a major concern for many countries and enterprises.

Currently, a remote meter reading for the electricity meter, water meter, or gas meter that has been proposed or implemented in Korea is mainly using a wired communication method using a telephone line or a power line communication method, or a wireless communication method such as a Zigbee or RF communication method.

However, in the case of the wired communication method, it is possible to perform additional services due to its high speed and large data processing capacity, but it is relatively expensive to install and operate the wired communication system compared to the wireless communication method. have. On the other hand, a wireless communication method such as ZigBee or RF communication has a problem in that it is inferior to the wired communication method in terms of transmission speed, transmission distance and data processing capacity. Recently, in order to solve the problems of the conventional communication method, a remote meter reading method using binary CDMA has been newly spotlighted.

However, since the binary CDMA uses the 2.4 GHz frequency band, which is an ISM band band such as Wi-Fi or ZigBee, there is a possibility that frequency interference occurs with the Wi-Fi or ZigBee. In particular, recently, due to the spread of smart phones, the possibility of interference between binary CDMA and Wi-Fi is seriously concerned. Of course, because the bandwidth is different for each technology, even if it is not seriously affected by interference, the direct and indirect effects on the transmission and reception of data cannot be avoided.

Therefore, there is a demand for a technology that can avoid or minimize frequency interference when transmitting and receiving data between binary CDMA, Wi-Fi, and Zigbee.

For this purpose, a technology for avoiding frequency interference between communication technologies using the same frequency through publication No. 10-2009-0092495, titled 'Method and apparatus for avoiding collision between communication systems in Zigbee communication' This has been disclosed. The above conventional technology measures a frame error rate of ZigBee nodes to determine whether there is interference between the ZigBee node and another communication system, and when the interference is present, the other communication if the interference exists. An interference arbiter for searching for a channel not used by the systems to mediate the interference, wherein the interference arbiter may change the channel of the Zigbee node to the channel when the search finds the channel, and finds the channel as a result of the search. If not present, the interference is mediated using time division multiple access (TDMA). According to the prior art, by preventing the frequency collision between the Zigbee communication device and other wireless communication system in the Zigbee communication, there is an effect that can reduce the communication failure rate and malfunction of the communication system.

However, the above-described prior art requires a WLAN communication module separately to check for WLAN interference, which may cause a cost increase of the product. In order to overcome this problem, continuous communication is required in order to observe interference in Zigbee communication without a WLAN communication module, which has a problem in that data transmission and reception speed is significantly reduced due to the nature of asynchronous communication. In addition, the process of searching for an idle channel is also less efficient than searching only for a channel having low possibility of interference when searching for an idle channel without any criteria.

The present invention provides a method and apparatus for avoiding frequency interference in binary CDMA communication, and a computer-readable recording medium for minimizing frequency interference with Wi-Fi or ZigBee which share 2.4GHz band in performing binary CDMA communication. The purpose.

More specifically, the present invention searches for an idle channel and performs communication using the corresponding channel in performing binary CDMA communication, and obtains an optimal channel by grasping reception sensitivity in real time while performing communication, thereby improving data communication quality. An object of the present invention is to provide a method, an apparatus, and a computer-readable recording medium for avoiding frequency interference in binary CDMA communication.

In addition, the present invention allows the slave to recognize the channel movement of the master within a short time by periodically receiving a synchronization signal from the master to minimize the down time due to the channel movement of the master to maintain a high communication quality Another object is to provide a method, apparatus, and computer-readable recording medium for avoiding frequency interference in CDMA communication.

According to an aspect of the present invention, a method for avoiding frequency interference in binary CDMA communication performed by a master, the method comprising: (a) searching an idle channel by checking an energy level of a primary channel; (b) selecting a channel having the lowest energy level among the main channels when an idle channel exists; (c) transmitting a beacon after setting the piconet value; (d) receiving a synchronization request signal from a slave; (e) transmitting and receiving data with the slave when synchronizing is allowed, and periodically checking data reception sensitivity during data transmission and reception; And (f) disconnecting synchronization with all slaves when a slave below the reference sensitivity is equal to or greater than a reference ratio among the slaves.

Preferably, when the idle channel does not exist in the main channel in the step (a), the step of searching the idle channel by sequentially checking the energy level of all channels including the main channel, and when there is an idle channel The method may further include selecting a channel having the lowest energy level among all the channels.

More preferably, the channel is characterized as being an idle channel when the measured energy level is less than or equal to a preset reference level.

In addition, the synchronization request signal received from the slave in the step (d) can be decrypted using a preset security key only when the slave encodes the synchronization request signal using the same security key. do.

In addition, the main channel is selected as a 3, 6, 8, 10 channel having a low probability of interference with the channels 1, 5, 9, 13 which is a scanning channel of the Wi-Fi.

In addition, the step (f) is characterized in that the synchronization is disconnected with all slaves when the reception sensitivity of 60% or more of the slaves is less than -80dB.

In addition, according to another aspect of the present invention, in a method of avoiding frequency interference of binary CDMA communication performed in a slave, (a) receiving a beacon from a master selected as an idle channel having the lowest energy level among the main channels to obtain the same piconet value; Checking to have; (b) selecting a master having the highest radio reception sensitivity among masters having the same piconet value and transmitting a synchronization request signal; (c) transmitting and receiving data to and from the master when the master allows synchronization and determining whether synchronization is interrupted; And (d) repeating steps (a) to (c) when synchronization with the master is lost.

Preferably, in the step (c), the slave periodically transmits and receives a synchronization signal with the master, characterized in that the slave recognizes in real time that the synchronization is disconnected when the master moves the channel.

Further, according to another aspect of the present invention, in the master constituting the frequency interference avoidance apparatus of binary CDMA communication, the energy level of the primary channel is examined to search for an idle channel, if there is an idle channel of the primary channel A channel search unit for selecting a channel having the lowest energy level; A communication unit for transmitting a beacon to a slave after setting a piconet value, receiving a synchronization request signal from the slave, and transmitting and receiving data with the slave; And a first wireless reception sensitivity determiner which periodically checks data reception sensitivity during a data transmission / reception process with the slave and disconnects synchronization with all slaves when a slave below a reference sensitivity is greater than or equal to a reference ratio. Is provided.

Preferably, the channel searcher, when there is no idle channel among the main channels, sequentially searches energy levels of all channels including the main channel, and searches for idle channels, and if there is an idle channel, among all the channels. The channel having the lowest energy level value is selected.

More preferably, the channel is characterized as being an idle channel when the measured energy level is less than or equal to a preset reference level.

The apparatus may further include a communication connection allowance unit configured to determine whether to allow communication with the slave by decrypting the synchronization request signal using a previously stored security key.

In addition, according to another aspect of the present invention, in the slave constituting the frequency interference avoidance apparatus of binary CDMA communication, a master selected as the idle channel having the lowest energy level among the main channels using the received beacon is the same piconet value Piconet determination unit for checking whether having; A second wireless reception sensitivity determination unit searching for a master having the highest wireless reception sensitivity among masters having the same piconet value; And a communication state determiner configured to determine whether synchronization with the master is interrupted in the process of transmitting and receiving data in synchronization with the master.

Preferably, the communication state determination unit, in real time when the master periodically transmitting and receiving the synchronization signal moves the channel is recognized that the synchronization is disconnected.

In addition to this, there is further provided a computer readable recording medium for recording a computer program for executing a method for implementing the present invention.

According to the present invention, when performing communication using binary CDMA, the master selects an idle channel having the lowest possibility of interference with other communication schemes to perform data communication, thereby preventing interference with Wi-Fi or Zigbee using the same frequency band. It can be minimized.

In addition, the present invention in the process of performing communication between the master and the slave in real time to check the radio reception sensitivity when the radio reception sensitivity is lowered below a certain level, the communication is stopped, other interference with other communication schemes are less likely It is possible to provide high communication quality by searching for and occupying idle channels to continue communication.

In addition, the present invention enables the slave to periodically recognize the channel movement of the master by transmitting and receiving a synchronization signal with the master in a short time to minimize the down time due to the channel movement of the master to maintain a high communication quality.

1 is a view showing the elements constituting the koinonia according to an embodiment of the present invention.
2 is a block diagram showing the configuration of a master constituting koinonia according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a frequency band used for data communication in binary CDMA and Wi-Fi and a channel in which binary CDMA is first occupied according to a preferred embodiment of the present invention.
4 is a block diagram showing the configuration of a slave constituting koinonia according to an embodiment of the present invention.
5 is a flow chart illustrating the operation of the master constituting the koinonia according to an embodiment of the present invention.
6 is a flowchart illustrating an operation of a slave constituting koinonia according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

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

1 is a view showing the elements constituting the koinonia according to an embodiment of the present invention.

Koinonia is a high-speed wireless personal area network (WPAN) technology designed to connect and communicate with short-range devices wirelessly. Koinonia's physical layer is based on binary CDMA, and the data link layer is composed of a media access control (MAC) layer and an adaptation layer. The physical layer using Koinonia's phase modulation method and multi-code spreading technology provides strong noise resistance and freely adjustable bandwidth, and the data link layer using this guarantees the quality of service for each traffic characteristic. It can support multimedia services such as voice and video.

Koinonia is based on an ad hoc network that can be configured without a network infrastructure. The devices participating in the Koinonia network are divided into master and slave according to their role, but all stations can operate as master and slave, and the master is selected according to the situation between the devices. This allows for free network configuration without the need for a separate network infrastructure.

In a personal wireless network, the number of devices constituting the network due to channel conditions and characteristics of personal mobile devices due to characteristics in a wireless environment may change significantly over time. This has a big impact on the bandwidth or propagation delay time allocated to each device, making it difficult to support real-time multimedia traffic services that require a certain level of quality of service. In Koinonia, one station of the network becomes a master and allocates and manages resources, thereby managing the connection quality of the network for each traffic.

In addition, the Koinonia is advantageous in that noise resistance, detailed and flexible resource allocation are possible by using binary CDMA technology. First of all, binary CDMA has a high noise resistance inherent in CDMA technology, which can provide excellent performance in a very noisy wireless network environment unlike wired. In addition, the bandwidth can be adjusted in code units according to the characteristics of binary CDMA to support flexible and detailed resource allocation.

Referring to FIG. 1, the koinonia may be configured of a plurality of stations. The station may be divided into a master and a slave according to its role. The master manages the entire Koinonia network and there can be only one in one network. The master controls the slave by broadcasting a beacon toward the slave. The slave may transmit and receive data under the control of the master. In addition, the slave may request its requirements from the master in the contention period.

In more detail, the master may transmit the beacon to provide timing of a superframe of Koinonia. In addition, it can manage service quality and power, or play a role in security and authentication. Koinonia can be configured when there are two or more stations operating on the same radio frequency channel within the personal activity area.

On the other hand, the piconet (Piconet) is composed of one master and one or more slaves, and the multi-Piconet may be composed of the first highest Piconet (Parent Piconet) and the child Piconet formed based on this. . Such a lower piconet may be composed of a child master and a slave that perform a slave role in an upper piconet and a master role in a lower piconet.

The resources available in Koinonia are Code Channel in Code Division Multiple Access (CDMA) and Time Slot in Time Division Multiple Access (TDMA). In the code division access scheme, when many channels are used at the same time, the transmission rate increases, but the error rate also increases. Therefore, it is possible to actively cope with the channel environment by changing the number of code channels for transmitting data according to the channel situation. A code channel can transmit data using all code channels in a good channel condition and a few channels in a bad channel environment. Time slots are managed by the master as an important resource of Koinonia, and can be distributed at the request of the slave and the judgment of the master.

Figure 2 is a block diagram showing the configuration of a master constituting koinonia according to an embodiment of the present invention.

Referring to FIG. 2, the master includes a channel search unit 100, a communication unit 110, a communication connection allowance unit 120, a first wireless reception sensitivity determination unit 130, a database 140, and a controller 150. It may include.

According to an embodiment of the present invention, the channel search unit 100, the communication unit 110, the communication connection allowance unit 120, the first wireless reception sensitivity determination unit 130, the database 140, and the control unit 150. ) May be program modules, at least some of which are in communication with each other. Such program modules may be included in the master in the form of operating systems, application modules, and other program modules, and may be physically stored on various known storage devices. In addition, these program modules may be stored in a remote storage device in communication with the master. These program modules include, but are not limited to, routines, subroutines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types as described below in accordance with the present invention.

First, according to an embodiment of the present invention, the channel search unit 100 performs a function of searching for a channel to be used for data transmission and reception during the initial operation of the master. In more detail, the channel searching unit 100 searches for idle channels by first searching for major channels among binary CDMA channels, and sequentially searches for all channels in idle mode when there is no idle channel among the major channels. Search. The main channel will be described in more detail with reference to FIG. 3. The channel search unit 100 measures an energy level of a corresponding channel during an idle channel search and selects a channel having the lowest energy level as an idle channel. In other words, in the case of a channel not occupied by other masters, it is determined that the lowest energy level among the channels is not preempted by another master by using a high probability that the energy level is measured low.

In more detail, the channel searching unit 100 searches for idle channels by sequentially searching the main channels first, and selects a channel having the lowest energy level among the main channels, but the energy level of the channel is equal to or less than a reference level. You can ask. The reference level may be set to a level of high probability that the channel is already preempted by another master. Therefore, when the energy level of the channel with the lowest energy level among the main channels does not exceed the reference level, the channel search unit 100 sequentially measures the energy level for all channels including the main channel, and the most energy level. This low measured channel can be preempted as a channel for data transmission and reception with the slave.

Next, according to an embodiment of the present invention, the communication unit 110 transmits a beacon to at least one slave, and performs a function of receiving a synchronization request signal from the slave receiving the beacon. In addition, the master forming the piconet performs a function of communicating with at least one slave using binary CDMA. A well-known communication module may be used as the communication unit 110, and the communication state through the communication unit 110 may be inspected in real time through the first wireless reception sensitivity determination unit 130.

Next, according to an embodiment of the present invention, the communication connection allowance unit 120 decrypts the synchronization request signal transmitted from the slave through the communication unit 110 by using a previously stored security key. It determines whether to allow communication with the server. For this purpose, the communication connection allowance unit 120 may be programmed to be decoded only when the synchronization signal transmitted from the slave is encoded using the same security key in the slave, and the security key may be a preset function. Can be assigned to each master and slave.

Next, according to an embodiment of the present invention, the first wireless reception sensitivity determination unit 130 performs a data communication with the connected slave, and measures the wireless reception sensitivity (RSSI) to continue the connection with the slave. To determine whether or not to do so. In more detail, when the reception sensitivity above the preset reference ratio among the slaves is less than the preset reference sensitivity, synchronization with all slaves connected to the master may be disconnected. When the applicant of the present invention judges through repeated experiments, when more than 60% of the number of slaves forming the piconet has a reception sensitivity of -80 dB or less, the channel to be used is preempted by another master or Wi-Fi or is subject to fatal interference. It can be seen that it is most efficient to block synchronization with all slaves. Of course, the reference sensitivity with respect to the reception sensitivity can be variously changed according to the selection by those skilled in the art.

Next, according to an embodiment of the present invention, the database 140 includes the channel search unit 100, the communication unit 110, the communication connection allowance unit 120, the first wireless reception sensitivity determination unit 130, and the control unit ( 150 stores data required for normal operation and stores various data including a synchronization request signal received from a connected slave. In more detail, the database 140 may provide the channel search unit 100 with a reference level used for searching for an idle channel, and determine whether to allow communication connection with the slave to the communication connection allowance unit 120. It can provide a security key used to In addition, a reference ratio or a reference sensitivity used to disconnect synchronization with all slaves connected to the first wireless reception sensitivity determination unit 130 may be provided.

Finally, according to an embodiment of the present invention, the controller 150 is the channel search unit 100, the communication unit 110, the communication connection allowance unit 120, the first wireless reception sensitivity determination unit 130, and It performs a function of controlling the flow of data between the database 140. That is, the controller 150 controls the flow of data to / from the outside or between each component of the master, thereby allowing the channel search unit 100, the communication unit 110, the communication connection allowance unit 120, Each of the first wireless reception sensitivity determination unit 130 and the database 140 controls to perform a unique function.

FIG. 3 is a diagram illustrating a frequency band used for data communication in binary CDMA and Wi-Fi and a channel in which binary CDMA is first occupied according to a preferred embodiment of the present invention.

Referring to FIG. 3, the frequency bands used in binary CDMA are 11 channels in total, and the center frequency of each channel may be divided into channels having a bandwidth of about 8 MHz. Since channel 11 is used as an experimental frequency, channels 1 to 10 can be mainly used as scanning channels.

Meanwhile, the frequency band used in Wi-Fi is 13 channels, and the center frequency of each channel may be divided into channels having a bandwidth of about 5 MHz. Channels 1, 5, 9, and 13 of the channels used in the Wi-Fi are mainly used according to the government's recommendation, and therefore, the same frequency band as those of the channels 1, 5, 9, and 13 is relatively Wi-Fi. Interference functionality thereof can be increased.

Therefore, according to the present invention, channels 3, 6, 8, and 10 in binary CDMA, which have the least possibility of interference with channels 1, 5, 9, and 13 in Wi-Fi, are used as the primary channels for data transmission and reception. Done.

Accordingly, the channel searching unit 100 determines whether the main channel is an idle channel by setting channels 3, 6, 8, and 10, which are selected channels as the main channel, avoiding the Wi-Fi center frequency, and idles among the main channels. If the channel does not exist, the remaining channels are sequentially searched to search for idle channels.

4 is a block diagram showing the configuration of a slave constituting koinonia according to an embodiment of the present invention.

Referring to FIG. 4, the slave includes a communication unit 200, a piconet determination unit 210, a second wireless reception sensitivity determination unit 220, a communication state determination unit 230, a database 240, and a controller 250. It may include.

According to an embodiment of the present invention, the communication unit 200, the piconet determination unit 210, the second wireless reception sensitivity determination unit 220, the communication state determination unit 230, the database 240, and the controller 250 ) May be program modules, at least some of which are in communication with each other. Such program modules may be included in the slave in the form of operating systems, application modules, and other program modules, and may be physically stored on various known storage devices. In addition, such program modules may be stored in a remote storage device capable of communicating with a slave. These program modules include, but are not limited to, routines, subroutines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types as described below in accordance with the present invention.

First, according to an embodiment of the present invention, the communication unit 200 receives a beacon from the master, and performs a function of transmitting a synchronization request signal to the master. In addition, it performs a function of communicating with the master forming the piconet using binary CDMA.

Next, according to an embodiment of the present invention, the piconet determination unit 210 determines the same master as the piconet value assigned to the slave by examining the piconet value that is a logical network identifier from the beacon received from the master. do. The piconet value is a value assigned to the master and the slave to prevent the plurality of binary CDMA networks from being present on the same channel. The master and the slave may communicate with each other only with devices having the same piconet.

Next, according to an embodiment of the present invention, the second wireless reception sensitivity determiner 220 performs a function of measuring the wireless reception sensitivity with each master after receiving the beacon from the master. The slave transmits a synchronization request signal to a master having the highest sensitivity among the wireless reception sensitivity values thus measured. In addition, the second wireless reception sensitivity determination unit 220 has the highest wireless reception sensitivity in performing data communication among masters having the same piconet value as the piconet value given to the slave when synchronization with the master that is transmitting or receiving data is disconnected. Perform a function to search the master. The slave finds a master having excellent wireless reception sensitivity through the above process and transmits a synchronization request signal to the master through the communication unit 200 to continue transmitting and receiving data.

Next, according to an embodiment of the present invention, the communication state determination unit 230 performs a function of determining whether the synchronization between the slave and the master is disconnected. Since the slave periodically transmits and receives a synchronization signal (within a few msec) with the master, when the master disconnects from the slave and moves to another channel, the slave may recognize in real time that the synchronization with the master has been lost. The communication state determination unit 230 checks whether the synchronization with the master is disconnected, and provides information so that the slave may search for another channel as soon as synchronization is interrupted and search for a master having excellent radio reception sensitivity based on this. As such, the communication state determination unit 230 may determine in real time that the communication with the master has been interrupted, and thus the communication impossible time due to the channel movement of the master is extremely short, which makes it difficult for the user to feel this.

Next, according to an embodiment of the present invention, the database 240 is the communication unit 200, the piconet determination unit 210, the second wireless reception sensitivity determination unit 220, the communication state determination unit 230 and the control unit ( 250 stores data required for normal operation and stores various data including beacons received from the connected master. In more detail, the database 240 may provide a piconet value that is assigned to distinguish a communicable device, and may provide a security key used to encode a synchronization signal to be transmitted to the master.

Finally, according to an embodiment of the present invention, the control unit 250 is the communication unit 200, the piconet determination unit 210, the second wireless reception sensitivity determination unit 220, the communication state determination unit 230, and the database It performs a function of controlling the flow of data between the 240. That is, the controller 250 controls the flow of data to / from the outside or between the components of the slave, thereby communicating the communication unit 200, the piconet determination unit 210, and the second wireless reception sensitivity determination unit ( 220, the communication state determiner 230, and the database 240 control to perform unique functions.

5 is a flow chart illustrating the operation of the master constituting the koinonia according to an embodiment of the present invention.

Referring to FIG. 5, the master searches for an idle channel by checking energy levels of major channels (S100). On the basis of the checked energy level, it is determined whether an idle channel exists among the main channels (S110), and when there is an idle channel, preempt the channel having the lowest energy level among the idle channels as a channel to communicate with a slave. (S120). If the idle channel cannot be detected in step S110, the energy levels of the entire channels 1 to 10 including the main channel are sequentially examined (S130). On the basis of the checked energy level, it is determined whether an idle channel exists among all channels (S140). If there is an idle channel, the channel having the lowest energy level among the idle channels is preempted as a channel for communicating with the slave (S150). If the idle channel cannot be detected in step S150, the process returns to step S100 to search for an idle channel.

When the idle channel is searched in the above manner, the master sets a piconet value and transmits a beacon including information about the beacon to at least one slave (S160). Receive a synchronization request signal from the slave receiving the beacon (S170), and determines whether to allow the synchronization (S180). When it is determined to allow synchronization, communication with the slave is initiated to transmit and receive data, and the wireless reception sensitivity with each slave is checked in real time in the process of transmitting and receiving data (S190). On the basis of the wireless reception sensitivity measured in step S190 it is determined whether the slave is less than the reference sensitivity or more than the reference ratio (S200). If it is determined in step S200 that the slave is less than the reference sensitivity is more than the reference ratio to block the synchronization with all slaves (S210). However, if it is determined in step S200 that the slave with the reference sensitivity is not greater than the reference ratio, the data is transmitted and received with the slave using the preempted channel.

6 is a flowchart illustrating an operation of a slave constituting koinonia according to an exemplary embodiment of the present invention.

Referring to FIG. 6, the slave receives a beacon from the master (S300). Based on the received beacons, it is checked whether the master has the same piconet value as itself (S310). If the master has the same piconet value as its own, the wireless reception sensitivity with the master is checked (S320). On the other hand, when the master has a different piconet value from itself, the process returns to step S300 and receives a beacon from another master. In this process, the wireless reception sensitivity is checked and a master having the highest wireless reception sensitivity is selected (S330), and a synchronization request signal is transmitted to the master selected in step S330 (S340). When the master allows synchronization according to the synchronization request signal, it transmits and receives data with the master (S350). In the process of transmitting / receiving data, it is determined whether the synchronization with the master is blocked (S360). If the synchronization is blocked, the process returns to step S100 and the above process is repeated. Continue sending and receiving data.

Embodiments according to the present invention described above may be implemented in the form of program instructions that can be executed by various computer components and recorded in a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the computer-readable recording medium may be those specially designed and constructed for the present invention, or may be known and available to those skilled 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, and magneto-optical media such as floptical disks. optical media) and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. 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. The hardware device may be configured to operate as one or more software modules for performing the processing according to the present invention, and vice versa.

Although the present invention has been described by specific embodiments such as specific components and the like, but the embodiments and the drawings are provided to assist in a more general understanding of the present invention, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations can be made from these descriptions.

Accordingly, the spirit of the present invention should not be limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the appended claims, fall within the scope of the spirit of the present invention. I will say.

100: channel search unit
110, 200: communication unit
120: communication connection allowance
130: first wireless reception sensitivity determination unit
140, 240: Database
150, 250: control unit
210: piconet determination unit
220: second wireless reception sensitivity determination unit
230: communication state determination unit

Claims (15)

In the frequency interference avoidance method of binary CDMA communication performed in the master,
(a) searching for idle channels by examining energy levels of primary channels;
(b) selecting a channel having the lowest energy level among the main channels when an idle channel exists;
(c) transmitting a beacon after setting the piconet value;
(d) receiving a synchronization request signal from a slave;
(e) transmitting and receiving data with the slave when synchronizing is allowed, and periodically checking data reception sensitivity during data transmission and reception; And
and (f) disconnecting synchronization with all slaves when a slave below the reference sensitivity is equal to or greater than a reference ratio among the slaves. The method of claim 1,
If there is no idle channel among the main channels in step (a),
Sequentially examining energy levels of all channels including the primary channel to search for idle channels; and
And selecting a channel having the lowest energy level value among all the channels when there is an idle channel. The method of claim 2,
And the channel is regarded as an idle channel when the measured energy level is less than or equal to a predetermined reference level. The method of claim 1,
The synchronization request signal received from the slave in the step (d),
And the slave can decode using a predetermined security key only when the slave encodes the synchronization request signal using the same security key. The method of claim 1,
The main channel is a frequency interference avoidance method of binary CDMA communication, characterized in that selected as the 3, 6, 8, 10 channel is less likely to interfere with the channel 1, 5, 9, 13 of the scanning channel of the Wi-Fi. The method of claim 1,
The step (f)
Method for avoiding frequency interference of binary CDMA communication characterized in that the synchronization is disconnected with all slaves when the reception sensitivity of 60% or more of the slave is less than -80dB. delete delete In the master constituting the frequency interference avoidance device of binary CDMA communication,
A channel searcher for searching for an idle channel by checking energy levels of main channels and selecting a channel having the lowest energy level among the main channels when an idle channel exists;
A communication unit for transmitting a beacon to a slave after setting a piconet value, receiving a synchronization request signal from the slave, and transmitting and receiving data with the slave; And
And a first wireless reception sensitivity determiner configured to periodically check data reception sensitivity during a data transmission / reception process with the slave to disconnect synchronization with all slaves when a slave below a reference sensitivity is greater than or equal to a reference ratio. The method of claim 9,
The channel search unit,
If there is no idle channel among the main channels, the energy level of all channels including the main channel is sequentially examined to search for the idle channel,
And when the idle channel is present, selecting the channel having the lowest energy level value among all the channels. The method of claim 10,
And the channel is regarded as an idle channel when the measured energy level is less than or equal to a predetermined reference level. The method of claim 9,
And a communication connection allowance unit configured to determine whether to allow communication with the slave by decrypting the synchronization request signal using a pre-stored security key. delete delete A computer readable recording medium having recorded thereon a computer program for executing the method according to any one of claims 1 to 6.

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