KR20140076013A - Mobile gateway of the wireless sensor network and method for transmitting sensing data in the mobile gateway - Google Patents

Abstract

Disclosed are a mobile gateway collecting sensing data of sensors in a wireless sensor network and transmitting the sensing data to a server; and a method for transmitting the sensing data using the same. A mobile gateway, which connects sensors with a server in a wireless sensor network, comprises: a sensor information collecting means for collecting sensing data of the sensors; a gateway selecting means classifying the sensors into a first group and a second group, selecting another mobile gateway positioned closest to a sensor included in the second group, and asking the selected mobile gateway for a data report about the sensor included in the second group; and a sensor information reporting means transmitting sensing data of a sensor included in the first group to the server.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of transmitting sensing data of a mobile gateway and a mobile gateway of a wireless sensor network,

The present invention relates to a wireless sensor network technology, and more particularly, to a mobile gateway for collecting and transmitting sensing data of sensors in a wireless sensor network and a method for transmitting sensing data of the mobile gateway.

A wireless sensor network (WSN) connects to an external network through a network system and processes and manages information input through various sensors in real time. The ultimate goal of such a wireless sensor network system is to provide computing and communication functions to all objects, thereby realizing an environment in which communication is possible regardless of network, device and service anytime and anywhere.

The configuration of the wireless sensor network system detects real-time perception information of objects or surrounding environment information, routes information transmitted from sensors and sensors equipped with a communication module, and transmits the information to a management server through a broadband communication network And a gateway. The sensor can be connected to the existing infrastructure such as satellite communication, wireless LAN, Bluetooth and wired Internet through the gateway.

In this wireless sensor network system, most of the gateways are fixedly installed and connected to the sensors by wire. However, due to the development of wireless technology, sensors and gateways tend to communicate wirelessly, and fixed gateways are often installed in independent spaces, which is often not suitable for the installation environment of sensors. It is being replaced by a mobile gateway.

In this way, wireless communication is used in the communication between the sensor and the gateway, and the mobile gateway is widely used, so that it takes a lot of power to collect the sensing data of the sensor, or the sensing data can not be collected accurately. In other words, when the distance between the mobile gateway and the sensor is above a certain level, the signal sensitivity of the sensor becomes worse. If the sensing data is not collected properly by the mobile gateway, or when the signal sensitivity is not good, The gateway needs to consume more power.

Korean Patent No. 10-1192443 (issued October 18, 2012)

It is an object of the present invention to provide a mobile gateway for collecting sensing data of sensors in a wireless sensor network and transmitting the sensing data to a server and a method of transmitting sensing data using the same.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to an aspect of the present invention, a mobile gateway for connecting sensors and a server in a wireless sensor network includes sensor information collection means for collecting sensing data of the sensors; Classifying the sensors into a first group and a second group, selecting another mobile gateway closest to the sensors belonging to the second group, and reporting data to sensors belonging to the second group to another selected mobile gateway A gateway selection means for requesting a gateway to select a gateway; And sensor information reporting means for transmitting sensing data of the sensors belonging to the first group to the server.

The gateway selecting means classifies the sensors whose received signal strength is larger than the threshold value into the first group and the sensors whose received signal strength is smaller than the threshold value into the second group.

The gateway selecting means can select a mobile gateway having the largest received signal strength from the sensor belonging to the second group.

Wherein the mobile gateway further comprises a neighbor list management means for collecting information of neighboring mobile gateways and creating a neighbor list, and the gateway selecting means can select at least one of the neighbor mobile gateways recorded in the neighbor list .

Wherein the gateway selecting means broadcasts a message including identification information of a sensor belonging to the second group to the peripheral mobile gateway and compares the signal strength of the sensor included in the received message in response to the message to select a mobile gateway .

According to another aspect of the present invention, there is provided a mobile gateway for connecting sensors and a server in a wireless sensor network, comprising: sensor information collection means for collecting sensing data of the sensors; Gateway selecting means for exchanging information between the other mobile gateway and the sensors to select a mobile gateway for reporting the sensing data for each sensor among the other mobile gateway and the mobile type gateway; And sensor information reporting means for transmitting the sensing data of the sensor selected by the selecting means to the server in the mobile gateway, to the server.

The mobile gateway according to another aspect further includes a neighbor list management unit for collecting information of the neighboring mobile gateway and creating a neighbor list, and the gateway selecting unit selects the neighbor mobile gateway and the sensor Can be exchanged.

The gateway selecting means may select a mobile gateway having the largest received signal strength from the sensor for each sensor as a mobile gateway for each sensor.

According to another aspect of the present invention, there is provided a method for transmitting sensing data of a mobile gateway connecting sensors and a server in a wireless sensor network, the method comprising: collecting sensing data of the sensors; Classifying the sensors into a first group and a second group; Selecting another mobile gateway closest to the sensor belonging to the second group; Requesting data to be reported to a sensor belonging to the second group to another selected mobile gateway; And transmitting sensing data of a sensor belonging to the first group to the server.

The classifying step may classify the sensors having received signal strengths larger than the threshold value into the first group and classify the sensors having the received signal strength values smaller than the threshold value into the second group.

The selecting may select a mobile gateway having the largest received signal strength from the sensor belonging to the second group.

The method may further include collecting information of neighboring mobile gateways to create a neighbor list, and the selecting step may select at least one neighboring mobile gateway recorded in the neighbor list.

Wherein the selecting comprises: broadcasting a message to the neighboring mobile gateway that includes identification information of a sensor belonging to the second group; And selecting a mobile gateway by comparing signal strengths of sensors included in a message received in response to the broadcast message.

According to another aspect of the present invention, there is provided a method for transmitting sensing data of a mobile gateway connecting sensors and a server in a wireless sensor network, the method comprising: collecting sensing data of the sensors; Exchanging information of the other mobile gateway with the sensors; Selecting a mobile gateway from among the other mobile gateway and the mobile gateway for reporting the sensing data for each sensor based on the exchanged information; And transmitting the sensed data of the sensor selected by the mobile gateway to the server.

In sensing and collecting sensing data using a mobile gateway in a wireless sensor network, sensing data of a sensor having a low sensitivity is transmitted through a mobile gateway located close to the sensor, thereby reducing power consumption of the sensor and the mobile gateway So that it can be efficiently managed.

1 is a block diagram of a wireless sensor network according to an embodiment of the present invention.
2 is a block diagram of a mobile gateway according to an embodiment of the present invention.
3 is a diagram showing a configuration of a sensor processing program according to an embodiment of the present invention.
4 is a flowchart illustrating a sensing data transmission method according to an embodiment of the present invention.
5 is a flowchart illustrating a sensing data transmission method according to another embodiment of the present invention.

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which: There will be. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a wireless sensor network according to an embodiment of the present invention.

1, a wireless sensor network according to the present embodiment includes a plurality of sensors 110-1 to 110-N, a plurality of mobile gateways 130-1 to 130-M, A communication network 150 and a server 170. [

The plurality of sensors 110-1 to 110-N are attached to a body or an object of an individual to provide context information of a temperature, a humidity, and a user's health state of the service environment in which the user is located in real time And has various communication protocols and data formats. Herein, the context information is information (information) defining characteristics of a situation, such as a person, a place, an object, an object, and a time, which affect interaction between a user and another user, a system, or a device in relation to the ubiquitous computing A user context such as a printer, a display, and a workstation, a user context such as a user's profile, a location, a surrounding user, a lighting, a noise level, a traffic state, Temperature, etc., physical context, time, week, month, and season.

The plurality of sensors 110-1 to 110-N sense the surrounding situation information and transmit the sensed data to the server 170 through the mobile gateways 130-1, ..., and 130- Lt; / RTI > Preferably, the plurality of sensors 110-1, ..., 110-N send sensing data to the gateways 130-1, ..., 130-M when a request is received from the gateways 130-1, 130-M, or may transmit sensing data to the mobile gateways 130-1, ..., 130-M upon arrival of the self-sensing data reporting period. The sensors 110-1 to 110-N and the mobile gateways 130-1 to 130-M transmit and receive data by short-distance communication such as Bluetooth, ZigBee, and WiFi.

A plurality of mobile gateways 130-1 to 130-M collect sensing data from a plurality of sensors 110-1 to 110-N upon arrival of a sensing data report period, To the server 170 via the Internet. A plurality of mobile gateways 130-1,..., And 130-M can be moved and carried by the operator as a portable terminal, for example.

The communication network 150 is a communication network such as Global System for Mobile Communication (GSM), Enhanced Data GSM Environment (EDGE), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), and Time Division Multiple Access And includes a network that has not yet been developed at the time of filing of the present application.

Any one of the plurality of mobile gateways 130-1, ..., and 130-M may be a master mobile gateway, and the remainder may be a slave mobile gateway. The master mobile gateway performs the reporting function of the sensing data, and the slave mobile gateway can perform the reporting function of the sensing data when requested by the master mobile gateway.

Specifically, when collecting the sensing data from the plurality of sensors 110-1, ..., 110-N, the master mobile gateway analyzes the strength of the signal received from the sensors and has a received signal strength smaller than the threshold A plurality of slave mobile gateways, and a response message to the plurality of slave mobile gateways, and analyzing the response message to analyze the responses of the slaves, And requests the reporting of the sensing data. Here, the distance to the sensors can be determined based on the received signal strength of the sensors received at the gateway. It is determined that the gateway having the largest received signal strength is closest to the sensor.

Upon receipt of the data reportable inquiry message broadcasted from the master mobile gateway, the slave mobile gateway detects the reception of the sensors 110-1, ..., 110-N corresponding to the identification information of the sensors included in the message Measures a signal strength, and returns a response message including the measured received signal strength and identification information of the sensors.

That is, the master mobile gateway does not transmit the sensing data directly to the sensors among the plurality of sensors 110-1, ..., and 110-N, Finds a nearby slave mobile gateway and requests the corresponding slave mobile gateway to transmit the sensing data of the corresponding slave mobile gateway. Accordingly, the mobile gateways 130-1,..., And 130-M existing at the optimal distance to the sensors can report accurate sensing data.

Alternatively, each of the plurality of mobile gateways 130-1, ..., and 130-M may operate in a general operation mode to collect sensing data from the plurality of sensors 110-1, ..., 110-N The mobile stations 130-1, 130-2,... 130-1, 130-2,... 130-4 can analyze the received signal strengths of the sensors and exchange the received signal strength and identification information of the analyzed sensors to classify the sensors to be in charge of each sensor. And 130-M collects sensing data for the sensor groups in charge and transmits them to the server 170 through the communication network 150. [ Wherein the classification of the sensors is based on the signal strength of the sensors.

For example, when there are three mobile gateways and a signal of the sensor 1 is received at each mobile gateway, the mobile gateway having the largest received signal strength from the sensor 1 among the three mobile gateways reports the sensing data of the corresponding sensor 1 As shown in FIG.

2 is a block diagram of a mobile gateway according to an embodiment of the present invention.

2, the mobile gateway 130 according to the present embodiment includes a memory 202, a memory controller 204, one or more processing units (CPUs) 206, a peripheral interface 208, an input / output ) Subsystem 210, a display 212, an input device 214, and an RF circuitry 216. These components communicate through one or more communication buses or signal lines 218. The various components shown in FIG. 2 may be implemented in hardware, software, or a combination of both hardware and software, including one or more signal processing and / or application specific integrated circuits.

Memory 202 may include a high speed random access memory and may also include one or more magnetic disk storage devices, non-volatile memory such as flash memory devices, or other non-volatile semiconductor memory devices. In some embodiments, the memory 202 may include a storage device, e.g., RF circuitry 216, located remotely from the one or more processors 206, and an Internet, intranet, local area network (WLAN) , A Storage Area Network (SAN), or the like, or a suitable combination thereof, via a communication network (not shown). Access to the memory 202 by other components of the mobile gateway 130, such as the CPU 206 and the peripheral interface 208, may be controlled by the memory controller 204.

The peripheral interface 208 connects the input / output peripheral of the device with the CPU 206 and the memory 202. The one or more processors 206 perform various functions and process data for the mobile gateway 130 by executing various software programs and / or instruction sets stored in the memory 202.

In some embodiments, peripheral interface 208, CPU 206 and memory controller 204 may be implemented on a single chip, such as chip 211. In some other embodiments, these may be implemented as separate chips.

The I / O subsystem 210 provides an interface between the input / output peripheral of the mobile gateway 130, such as the display 212 and other input devices 214, and the peripheral interface 208.

The display 212 may be a liquid crystal display (LCD) technology or a light emitting polymer display (LPD) technology, and the display 212 may be a capacitive, resistive, infrared or other touch display.

CPU 206 is a processor configured to perform operations associated with mobile gateways 130 and to execute instructions that may be executed by the processor 206 using instructions retrieved from memory 202, Reception and manipulation of data can be controlled.

In some embodiments, software components are installed (installed) in memory 202, such as an operating system 232, a graphics module (instruction set) 234, and a sensor processing program (instruction set)

The operating system 232 may be an embedded operating system such as, for example, Darwin, RTXC, LINUX, UNIX, OS X, WINDOWS or VxWorks, and may include general system tasks (e.g., memory management, Storage control, power management, and the like), and facilitates communication between various hardware and software components.

Graphics module 234 includes a number of well known software components for providing and displaying graphics on display 212. The term "graphics" includes, without limitation, text, web pages, icons (e.g., user interface targets including soft keys), digital images, video, animations, .

The RF circuit 216 transmits and receives electromagnetic waves. The RF circuit 216 converts electrical signals to electromagnetic waves and vice versa and communicates with the communication network and other mobile gateways and communication devices through the electromagnetic waves. The RF circuitry 216 may include, for example, an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC chipset, a subscriber identity module But are not limited to, well known circuits for performing such functions. The RF circuitry 216 may be any of a variety of communication technologies, including the Internet, referred to as the World Wide Web (WWW), a network such as an intranet and / or a cellular telephone network, a wireless LAN and / or a metropolitan area network (MAN) To communicate with other devices. The wireless communication may be implemented in a variety of communication systems such as Global System for Mobile Communication (GSM), Enhanced Data GSM Environment (EDGE), wideband code division multiple access (WCDMA), code division multiple access (CDMA), time division multiple access (TDMA) Wi-Fi (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g and / or IEEE 802.11n), voice over Internet Protocol (VoIP), Wi-MAX, including but not limited to protocols for instant messaging and / or short message service (SMS) or other suitable communication protocols including communication protocols not yet developed at the time of filing of the present application, Any of the techniques can be used.

The sensor processing program 236 collects sensing data from the plurality of sensors 110-1 to 110-N via the RF circuit 216 and transmits them to the server 170 via the RF circuit 216 . The sensor processing program 236 will be described in detail with reference to FIG.

Referring to FIG. 3, the sensor processing program 236 includes a mode setting unit 310, a neighbor list management module 330, a sensor setting unit 330, An information collecting module 350, a gateway selecting module 370, and a sensor information reporting module 390.

The mode setting unit 310 sets the mobile gateway to one of the master mode, the slave mode, and the general mode.

The Naver list management module 330 operates regardless of the operation mode, collects information of mobile gateways existing in the vicinity, creates a Naver list, and stores and manages the Naver list. Preferably, the neighbor risk management module 310 transmits a beacon signal and collects information on neighboring mobile gateways from a response signal to the beacon signal to create a neighbor list.

The sensor information collection module 350 collects sensing data from the plurality of sensors 110-1, ..., 110-N. In the master mode, the sensor information collection module 350 collects sensing data regardless of the neighboring mobile gateway, collects sensing data in response to a request from another mobile gateway in the master mode in the slave mode, Collects sensing data in cooperation with the gateway.

The sensor information collection module 350 can collect sensing data by transmitting a sensing data request to a plurality of sensors 110-1 to 110-N when a sensor information reporting period arrives, The sensors 110-1,..., 110-N can collect the sensing data transmitted by the sensor information reporting period itself.

The gateway selection module 370 operates as follows according to the operation mode.

master mode

The gateway selection module 370 classifies sensors having received signal strengths smaller than the threshold among the plurality of sensors 110-1, ..., 110-N and selects a slave mobile gateway closest to the classified sensors And requests the selected slave mobile gateway to report the sensing data of the classified sensors.

The gateway selection module 370 broadcasts a data reportable inquiry message including the identification information of the classified sensors to neighboring slave mobile gateways managed by the neighbor list management module 330, And requests the report of the sensing data by selecting the gateway closest to the sensors among the slave mobile gateways sent. The response message includes received signal strength and identification information from the sensors, and the gateway selection module 370 selects a slave mobile gateway having the largest received signal strength for each sensor to request reporting of sensing data.

Slave mode

Upon receiving the data reportable inquiry message including the identification information of the sensor from the master mobile gateway, the gateway selection module 370 measures the received signal strength from the sensors corresponding to the identification information of the sensor, A response message including the signal strength and the identification information of the sensor to the master mobile gateway, and receives a report request of the sensing data from the master mobile gateway.

Normal mode

The gateway selection module 370 exchanges received signal strengths and identification information of the mobile gateways and sensors managed by the neighbor list management module 330 to select a gateway for reporting the sensing data of the sensors. The gateway selection module 370 compares the received signal strengths of the sensors collected from the mobile gateway and the received signal strengths of the sensors collected from the neighboring mobile gateway to obtain a mobile gateway having the largest received signal strength Select the sensing data of the sensor as the responsible person to report.

The sensor information reporting module 390 transmits the sensing data of the responsible sensors collected by the sensor information collecting module 350 to the server 170 based on the selection result of the gateway selection module 370.

4 is a flowchart illustrating a sensing data transmission method according to an embodiment of the present invention. In the embodiment referring to Fig. 4, the mobile gateway 1 is described as a master mobile gateway, and the remainder is described as a slave mobile gateway.

Referring to FIG. 4, in the arrival of the sensor information reporting period, the mobile gateway 1 in the master mode collects sensing data from a plurality of sensors 110-1 to 110-N (S401 and S403). Specifically, the mobile gateway 1 transmits a sensing data request message to the plurality of sensors 110-1,..., 110-N and receives sensing data in response thereto.

The mobile gateway 1 that has collected the sensing data classifies the sensors to be handled by the plurality of sensors 110-1 to 110-N based on the received signal strengths of the sensors (S405). That is, the sensors having received signal strengths larger than the threshold value are determined to be the sensors of the mobile gateway 1, and the sensors having the received signal strength values smaller than the threshold value are determined to be the other gateways.

In step S407, the mobile gateway 1 that classifies the sensors broadcasts a data reportable inquiry message including identification information of sensors that it will not be responsible for, to the nearby slave mobile gateways. The surrounding slave mobile gateways receiving the broadcasted message measure the received signal strength of the sensors corresponding to the identification information of the sensors included in the inquiry message and transmit a response message including information of the measured received signal strength to the mobile gateway 1 (S409).

In step S411, the mobile gateway 1 selects a slave mobile gateway that receives the largest received signal strength for each sensor based on the received signal strength of the sensors included in the response message received from the slave mobile gateways. In this embodiment, the mobile gateway M is selected among a plurality of slave mobile gateways.

The mobile gateway 1 transmits a sensing data report request including the identification information of the sensors to be handled by the mobile gateway M to the selected mobile gateway M (S413). Upon receiving the request, the mobile gateway M collects the sensing data from the sensors corresponding to the identification information of the sensors included in the request, and transmits the collected sensing data to the server 170 (S415, S417). In addition, the mobile gateway 1 also transmits sensing data of sensors to be handled to the server 170 (S419).

5 is a flowchart illustrating a sensing data transmission method according to another embodiment of the present invention.

5, when the sensor information reporting period arrives, the mobile gateways collect the sensing data from the plurality of sensors 110-1,..., 110-N (S501, S503, S505). Specifically, the mobile gateways send a sensing data request message to a plurality of sensors 110-1,..., 110-N and receive sensing data in response thereto.

The mobile gateways that collect the sensing data exchange the received signal strength of the sensors and identification information to select a gateway to be responsible for each sensor (S507). For example, when the received signal strength of the sensor 1 is -60 dBm in the mobile gateway 1 and -50 dBm in the mobile gateway M, the mobile gateway M is selected as the mobile gateway responsible for reporting the sensing data of the sensor 1.

When the selection of the mobile gateway to report the sensing data for each sensor is completed, each mobile gateway transmits sensing data of its own sensors to the server 170 (S509, S511).

The method of the present invention as described above may be embodied as a program and stored in a computer-readable recording medium (such as a CD-ROM, a RAM, a ROM, a floppy disk, a hard disk, or a magneto-optical disk).

While the specification contains many features, such features should not be construed as limiting the scope of the invention or the scope of the claims. In addition, the features described in the individual embodiments herein may be combined and implemented in a single embodiment. Conversely, various features described herein in a single embodiment may be implemented in various embodiments individually or in a suitable subcombination.

It is to be understood that, although the operations have been described in a particular order in the figures, it should be understood that such operations are performed in a particular order as shown, or that a series of sequential orders, or all described operations, . In some circumstances, multitasking and parallel processing may be advantageous. It should also be understood that the division of various system components in the above embodiments does not require such distinction in all embodiments. The above-described program components and systems can generally be implemented as a single software product or as a package in multiple software products.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

110-1, ..., 110-N: sensors 130-1, ..., 130-M: mobile gateway
150: Network 170: Server
310: mode setting unit 330: Naver list management module
350: sensor information collection module 370: gateway selection module
390: Sensor information reporting module

Claims (13)

A mobile gateway for connecting sensors and servers in a wireless sensor network,
Sensor information collection means for collecting sensing data of the sensors;
Classifying the sensors into a first group and a second group, selecting another mobile gateway closest to the sensors belonging to the second group, and reporting data to sensors belonging to the second group to another selected mobile gateway A gateway selection means for requesting a gateway to select a gateway; And
And sensor information reporting means for transmitting sensing data of the sensors belonging to the first group to the server. The method according to claim 1,
Wherein the gateway selecting means comprises:
Classifies the sensors whose received signal strength is larger than the threshold value into the first group and classifies the sensors whose received signal strength is smaller than the threshold value into the second group. 3. The method according to claim 1 or 2,
Wherein the gateway selecting means comprises:
And selects a mobile gateway having the largest received signal strength from the sensors belonging to the second group. 3. The method according to claim 1 or 2,
And neighbor list management means for collecting information of the neighboring mobile gateway and creating a neighbor list,
Wherein the gateway selecting means comprises:
And selects at least one neighboring mobile gateway recorded in the neighbor list. 5. The method of claim 4,
Wherein the gateway selecting means comprises:
Wherein the mobile gateway selects a mobile gateway by broadcasting a message including identification information of a sensor belonging to the second group to the neighboring mobile gateway and comparing signal strengths of the sensors included in a message received in response thereto, Gateway. A mobile gateway for connecting sensors and servers in a wireless sensor network,
Sensor information collection means for collecting sensing data of the sensors;
Gateway selecting means for exchanging information between the other mobile gateway and the sensors to select a mobile gateway for reporting the sensing data for each sensor among the other mobile gateway and the mobile type gateway; And
And sensor information reporting means for transmitting the sensing data of the sensor selected by the selecting means to be handled by the gateway of the mobile gateway to the server. The method according to claim 6,
And neighbor list management means for collecting information of the neighboring mobile gateway and creating a neighbor list,
Wherein the gateway selecting means comprises:
And exchanges information of the neighboring mobile gateway and the sensors recorded in the neighbor list. 8. The method according to claim 6 or 7,
Wherein the gateway selecting means comprises:
Wherein a mobile gateway having the largest received signal strength from the sensor for each sensor is selected as a mobile gateway in charge of each sensor. A method for transmitting sensing data of a mobile gateway connecting sensors and a server in a wireless sensor network,
Collecting sensing data of the sensors;
Classifying the sensors into a first group and a second group;
Selecting another mobile gateway closest to the sensor belonging to the second group;
Requesting data to be reported to a sensor belonging to the second group to another selected mobile gateway; And
And transmitting the sensing data of the sensor belonging to the first group to the server. 10. The method of claim 9,
Wherein said classifying comprises:
And classifying the sensors having received signal strengths larger than the threshold value into the first group and classifying the sensors having the received signal strength values smaller than the threshold value into the second group. 11. The method according to claim 9 or 10,
Wherein the selecting comprises:
Wherein the mobile gateway selects the mobile gateway having the largest received signal strength from the sensors belonging to the second group. 11. The method according to claim 9 or 10,
Further comprising the step of collecting information of the neighboring mobile gateway and creating a neighbor list,
Wherein the selecting comprises:
And selecting at least one of the neighboring mobile gateways recorded in the neighbor list. 13. The method of claim 12,
Wherein the selecting comprises:
Broadcasting a message including identification information of a sensor belonging to the second group to the neighboring mobile gateway; And
And selecting a mobile gateway by comparing signal strengths of the sensors included in a message received in response to the broadcasted message.

Images