Abstract:
A sensor network communication system interworking with a BWA communication system and a communication method therefor are provided. In a method for measuring a predetermined target in the sensor network communication system interworking with the BWA communication system, a mobile station or a server sends a measurement request for the predetermined target to a local controller over the BWA communication system. The local controller sends the measurement request to a predetermined sensor and actuator over a wireless communication protocol. The sensor and actuator measures the predetermined target and sends the measurement value to the local controller. The local controller sends a measurement result message based on the measurement value to the mobile station or the server.

Description:
PRIORITY  
       [0001]     This application claims priority under 35 U.S.C. §119 to an application entitled “Sensor Network Communication System Interworking with Broadband Wireless Access Communication System and Communication Method Therefor” filed in the Korean Intellectual Property Office on Aug. 4, 2005 and assigned Serial No. 2005-71246, the contents of which are herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a system and method for forming a network by installing sensors/actuators configured to have computing capability and communication capability through the integration of sensor network technology and Broadband Wireless Access (BWA) communication technology at predetermined locations, and transferring information collected at the sensors/actuators to a remote place over the network, simultaneously with invoking the sensors/actuators for a certain actuation.  
         [0004]     2. Description of the Related Art  
         [0005]     Conventionally, a sensor network provides wired connectivity between sensors/actuators and between the sensors/actuators and local controllers.  FIG. 1  illustrates the configuration of the conventional sensor network.  
         [0006]     Referring to  FIG. 1 , the conventional sensor network includes, in a predetermined area, a local controller  100  for providing control for the area and sensors/actuators  110  to  122 . The local controller  100  is configured to send information received from the sensors/actuators  110  to  122  to a central controller/monitor  104  over a Public Telephone Switched Network (PTSN)  102 . The central controller/monitor  104  is a main server for processing the information received from the local controller  100 .  
         [0007]     The local controller  100  actuates the sensors/actuators  100  to  122 , upon receipt of a control request from the central controller/monitor  104  via the PTSN  102 .  
         [0008]     A drawback with the above conventional sensor network is that because communications are conducted between the sensors/actuators  110  to  122  and the local controller  100  by a particular protocol and wired connectivity, an additional wired link must be installed for deployment of a new sensor/actuator.  
         [0009]      FIG. 2  illustrates the configuration of an improved sensor network using a Distributed Monitoring and Control System (DMCS), compared to the sensor network illustrated in  FIG. 1 .  
         [0010]     Referring to  FIG. 2 , sensors/actuators  210 ,  212  and  214  send signals to a local gateway  230  via transceivers/repeaters  220  and  222 , and the local gateway  230  transfers the signals to a server  240  and at least one of a workstation  242  and a laptop  246  over an Internet  200 . The transceivers/repeaters  220  and  222  function to relay signals between the local gateway  230  and the sensors/actuators  210 ,  212  and  214 .  
         [0011]     An actuation request from the server  240 , the workstation  242 , and the laptop  246  may be transferred to the sensors/actuators  210 ,  212  and  214  in the reverse path.  
         [0012]     The server  240 , the workstation  242 , and the laptop  246  are used for managing the sensors/actuators  214  under the local gateway  230  from a remote place. The server  240  may store information in a database  248 .  
         [0013]     As with the sensor network illustrated in  FIG. 1 , the improved sensor network also has the shortcoming that due to the wired connectivity between the local gateway  230  and the server  240 , a wired link must be established for installation of a new device.  
       SUMMARY OF THE INVENTION  
       [0014]     An object of the present invention is to substantially solve at least the above problems and/or disadvantages and to provide at least the advantages below. Accordingly, an object of the present invention is to provide a system and method for forming a network by installing sensors/actuators at predetermined locations, configured to have computing capability and communication capability through the introduction of BWA communication technology to a sensor network, and transferring information collected at the sensors/actuators to a remote place over the network, simultaneously with invoking the sensors/actuators for a predetermined actuation.  
         [0015]     The above object is achieved by providing a sensor network communication system interworking with a BWA communication system and a communication method therefor.  
         [0016]     According to one aspect of the present invention, in a sensor network communication system interworking with a BWA communication system, a local controller communicates with the BWA communication system, and sends a measurement request or an actuation request received from an MS or a server in the BWA communication system to a sensor and actuator over a wireless communication protocol. The sensor and actuator performs a measurement or an actuation on a predetermined target according to the measurement request or the actuation request received from the local controller.  
         [0017]     According to another aspect of the present invention, in a method for measuring a predetermined target in the sensor network communication system interworking with the BWA communication system, an MS or a server sends a measurement request for the predetermined target to a local controller over the BWA communication system. The local controller sends the measurement request to a predetermined sensor and actuator over a wireless communication protocol. The sensor and actuator measures the predetermined target and sends the measurement value to the local controller. The local controller sends a measurement result message based on the measurement value to the MS or the server.  
         [0018]     According to a further aspect of the present invention, in a method of performing a predetermined actuation in a sensor network communication system interworking with a BWA communication system, an MS or a server sends an actuation request for the predetermined actuation to a local controller over the BWA communication system. The local controller sends the actuation request to a predetermined sensor and actuator over a wireless communication protocol. The sensor and actuator performs the predetermined actuation and sends an actuation result to the local controller. The local controller sends the actuation result to the MS or the server.  
         [0019]     According to still another aspect of the present invention, in a method of reporting a measurement result about a predetermined target in a sensor network communication system interworking with a BWA communication system, a sensor and actuator compares a measurement of the predetermined target with a normal range. If the measurement is outside the normal range, the sensor and actuator sends the measurement to a local controller. The local controller sends a measurement result message based on the measurement to at least one of a mobile station, a server, and a predetermined facility over the BWA communication system. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:  
         [0021]      FIG. 1  illustrates the configuration of a conventional sensor network;  
         [0022]      FIG. 2  illustrates the configuration of a conventional sensor network using a DMCS;  
         [0023]      FIG. 3  illustrates the configuration of an Institute of Electrical and Electronics Engineers (IEEE) 802.16 system according to the present invention;  
         [0024]      FIG. 4  illustrates the configuration of a sensor network using the IEEE 802.16 system according to the present invention;  
         [0025]      FIG. 5  is a block diagram of a local controller according to the present invention;  
         [0026]      FIG. 6  is a block diagram of a sensor/actuator according to the present invention;  
         [0027]      FIG. 7  is a flowchart illustrating an operation of the local controller according to the present invention;  
         [0028]      FIG. 8  is a flowchart illustrating an operation of the sensor/actuator according to the present invention;  
         [0029]      FIG. 9  is a diagram illustrating a signal flow for a measurement/actuation procedure when a server or a Mobile Station (MS) generates a measurement or actuation request according to the present invention; and  
         [0030]      FIG. 10  is a diagram illustrating a signal flow for an operation for reporting an abnormal measurement in the sensor/actuator according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]     Preferred embodiments of the present invention will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.  
         [0032]     The present invention is intended to provide a system and method for communications over a wireless communication protocol in a sensor network.  
         [0033]      FIG. 3  illustrates the configuration of a BWA communication system according to the present invention. While the present invention is described in the context of an IEEE 802.16 system as the BWA communication system, it is obviously understood that the present invention is applicable to any other BWA communication system. IEEE 802.16 is a kind of wireless communication protocol that enables high-speed data communication at up to 6 Mbps even when an MS moves at high speed, for example, at 60 km/h.  
         [0034]     Referring to  FIG. 3 , the IEEE 802.16 system includes an Access Network (AN)  300  and an MS  330  wirelessly connected to the AN  300 .  
         [0035]     The AN  300  provides wireless connectivity in compliance with the IEEE 802.16 standards. The AN  300  is comprised of Radio Access Stations (RASs)  320 ,  322  and  324  for providing wireless communication services to the MS  330 , and an Access Control Router (ACR)  310  for interfacing the RASs  320 ,  322  and  324  with an Internet Protocol (IP) network, serving as a router for the Internet  200 , and exchanging information between the Internet  200  and the MS  330 .  
         [0036]      FIG. 4  illustrates the configuration of a sensor network using the IEEE 802.16 system according to the present invention.  
         [0037]     Referring to  FIG. 4 , the sensor network includes a local controller  410  for attaching to the IEEE 802.16 system at a predetermined location  400  and sending a measurement request or an actuation request received from an entity of the IEEE 802.16 system, and sensors/actuators  412  and  414  for measuring or operating upon receipt of the measurement or actuation request from the local controller  410 .  
         [0038]     In operation, when an MS  330  requests a measurement on the predetermined location  400  to the sensors/actuators  412  and  414 , the measurement request is sent to the local controller  410  over the IEEE 802.16 system.  
         [0039]     The local controller  410  forwards the measurement request to the sensors/actuators  412  and  414 . After measuring, the sensors/actuators  412  and  414  send the measurements to the local controller  410  which in turn forwards the measurements to the MS  330  over the IEEE 802.16 system.  
         [0040]     When the MS  330  requests an actuation of the sensors/actuators  412  and  414  for the predetermined location  400 , the actuation request is sent to the local controller  410  over the IEEE 802.16 system.  
         [0041]     The local controller  410  forwards the actuation request to the sensors/actuators  412  and  414 . After being actuated, the sensors/actuators  412  and  414  send the actuation result to the local controller  410  which in turn forwards the actuation result to the MS  330  over the IEEE 802.16 system.  
         [0042]     In accordance with the present invention, a server (not shown) responsible for managing the local controller  410  and the sensors/actuators  412  and  414  may issue a measurement request and an actuation request to the sensors/actuators  412  and  414 .  
         [0043]     Even when the server or the MS  330  generates no measurement requests, the sensors/actuators  412  and  414  perform a periodic measurement. If the measurement lies outside a normal range, the sensors/actuators  412  and  414  may report the abnormal measurement to the MS  330 , the server or a corresponding facility (e.g. a fire station).  
         [0044]     The local controller  410  and the MS  330  access the Internet  200  in compliance with IEEE 802.16.  
         [0045]      FIG. 5  is a block diagram of the local controller  410  according to the present invention. The local controller is labeled with reference numeral  500  in  FIG. 5 .  
         [0046]     Referring to  FIG. 5 , in the local controller  500 , a server radio transceiver  530  exchanges signals and data with the RASs  320  and  322  and the ACR  310  through an antenna  535 . The signals and data are processed in compliance with IEEE 802.16.  
         [0047]     A sensor/actuator radio transceiver  540  exchanges signals and data with the sensors/actuators  412  and  414  through an antenna  545 . The signals and data are processed in compliance with the Bluetooth standards or Wireless Local Area Network (WLAN) standards, i.e. IEEE 802.11a/b/g.  
         [0048]     A controller  520  provides overall control to the local controller  500 . For example, the controller  520  controls signal and data transmission/reception of the server radio transceiver  530  and the sensor/actuator radio transceiver  540 . The typical functionalities of the controller  520  will not be described herein.  
         [0049]     A memory  510  stores the micro-codes of programs used for processing and control of the controller  520  and reference data. It serves as a working memory for the controller  520 , which temporarily stores data generated during execution of programs. It also stores updatable data to be kept, such as setting values of the controller  520 .  
         [0050]      FIG. 6  is a block diagram of the sensor/actuator  412  or  414  according to an embodiment of the present invention. The sensor/actuator is denoted by reference numeral  600  in  FIG. 6 .  
         [0051]     Referring to  FIG. 6 , in the sensor/actuator  600 , a radio transceiver  630  sends/receives signals and data through an antenna  635 . The signals and data are processed in compliance with the standards for Bluetooth or the standards for WLAN, i.e. IEEE 802.11a/b/g.  
         [0052]     A controller  620  provides overall control to the sensor/actuator  600 . For example, the controller  620  controls the signal and data transmission/reception of the radio transceiver  630 . A detailed description of the typical functionalities of the controller  620  is not provided herein.  
         [0053]     A memory  610  stores the micro-codes of programs used for processing and control of the controller  620  and reference data. It serves as a working memory for the controller  620 , which temporarily stores data generated during execution of programs. It also stores updated data to be kept, such as setting values of the controller  620 .  
         [0054]     A sensor  640  is a device for measuring smoke, temperature, motion, and gas. Depending on the location of the sensor/actuator  600 , the sensor  640  may be equipped with at least one of the smoke, temperature, motion, and gas measuring functions. The sensor  640  sends the resulting measurement to the controller  620 .  
         [0055]     An actuator  650  is actuated upon request of the controller  620 . Actuations of the actuator  650  are those of an electric motor, including opening/closing a gas valve and switch-on/off of a predetermined device.  
         [0056]      FIG. 7  is a flowchart illustrating an operation of the local controller  500  according to the present invention.  
         [0057]     Referring to  FIG. 7 , the controller  520  of the local controller  500  determines whether received information indicates a measurement/actuation request to a particular sensor/actuator from a server or a user in step  710 .  
         [0058]     If the received information is not a request from the user or the server, which implies that the received information is an abnormal measurement report from the sensor/actuator  600 , the controller  520  analyzes the abnormal measurement report in step  730 .  
         [0059]     If the abnormal measurement report is associated with an emergency (e.g. gas leakage or fire alarm), the controller  520  notifies a corresponding facility (e.g. a fire station or gas company) of the emergency in step  790  and also notifies the server or the user of the emergency in step  795 .  
         [0060]     On the other hand, if the received information is a request from the server or the user in step  710 , the controller  520  determines whether the request is a measurement request or an actuation request in step  720 .  
         [0061]     In the case of the measurement request, the controller  520  requests a measurement to the sensor/actuator  600  in step  750  and receives the measurement from the sensor/actuator  600  in step  780 .  
         [0062]     In step  795 , the controller  520  sends the measurement to the server or the user.  
         [0063]     In the case of the actuation request in step  720 , the controller  520  sends the actuation request to the sensor/actuator  600  in step  740  and receives an actuation result from the sensor/actuator  600 , such as actuation success in step  770 .  
         [0064]     The controller  520  notifies the server or the user of the actuation result in step  795 . Then the controller  520  terminates the algorithm of the present invention.  
         [0065]      FIG. 8  is a flowchart illustrating an operation of the sensor/actuator  600  according to the present invention.  
         [0066]     Referring to  FIG. 8 , the controller  620  of the sensor/actuator  600  checks whether a measurement at the sensor  640  lies within a normal range in step  810 .  
         [0067]     If the measurement is outside the normal range, the controller  620  sends an abnormal measurement report to the local controller  500  in step  840 .  
         [0068]     If the measurement falls within the normal range, the controller  620  determines whether a request has been received from the local controller  500  in step  820 .  
         [0069]     Upon receipt of the request, the controller  620  determines whether the request is about measuring in step  850 .  
         [0070]     In the case of a measurement request, the controller  620  sends the measurement acquired in step  810  to the local controller  500  in step  890 .  
         [0071]     In the case of an actuation request, the controller  620  invokes the actuator  650  for a predetermined actuation in step  860  and sends the actuation result to the local controller  500  in step  870 . Then the controller  620  ends the algorithm of the present invention.  
         [0072]      FIG. 9  is a diagram illustrating a signal flow for a measurement/actuation procedure when a server or an MS generates a measurement or actuation request according to the present invention.  
         [0073]     Referring to  FIG. 9 , the MS  330  and a RAS/ACR  910  are located in a network, and a RAS/ACR  920 , the local controller  410 , and the sensor/actuator  412  are located in another network.  
         [0074]     In step  930 , the MS  330  is connected to the IEEE  802 . 16  system in the following procedure.  
         [0075]     (1) Ranging: the MS  330  performs ranging during network entry to correct its uplink data transmission timing and adjust its frequency and power.  
         [0076]     (2) Subscriber Station (SS) Basic Capabilities (SBC): the MS  330  exchanges physical parameters and authentication policy information with the RAS  910 .  
         [0077]     (3) Privacy Key Management (PKM): key information necessary for authenticating Medium Access Control (MAC) messages and traffic encryption is exchanged between the MS  330  and the RAS  910 . In this PKM phase, authentication of the MS  330  and subscriber authentication are carried out.  
         [0078]     (4) Registration (REG): registration information including Service Flow (SF) and IP Convergence Sublayer (CS) capability information, mobility information, and Automatic Repeat reQuest (ARQ) parameters is exchanged between the MS  330  and the ACR  910 .  
         [0079]     (5) Dynamic Service Addition (DSA): to establish a new connection between the MS  330  and the RAS  910 , a Connection ID (CID) is allocated and the SF and IP CS information of the connection is exchanged between them. Then the MS  330  is connected to the IEEE 802.16 communication system.  
         [0080]     To enable the RAS/ACR  910  and the local controller  410  to be able to communicate with each other at any time, they are kept in a connected state in step  940 . Likewise, the local controller  410  and the sensor/actuator  412  are kept in a connected state to enable communications between them at any time in step  945 .  
         [0081]     The MS  330  sends a measurement request message to the local controller  410  in step  950 , and the local controller  410  forwards the measurement request message to the sensor/actuator  412  in step  960 .  
         [0082]     The sensor/actuator  412  responds to the local controller  410  with a measurement result message containing a measurement in step  970  and the local controller  410  forwards the measurement result message to the MS  330  in step  980 .  
         [0083]     If the MS  950  sends an actuation request message to the local controller  410  in step  950 , and the local controller  410  forwards the actuation request message to the sensor/actuator  412  in step  960 .  
         [0084]     The sensor/actuator  412  performs the requested actuation and responds to the local controller  410  with an actuation result message containing an actuation result in step  970  and the local controller  410  forwards the actuation result message to the MS  330  in step  980 .  
         [0085]     While not shown, when a predetermined server sends a measurement/actuation request instead of the MS  330 , the same procedure is performed.  
         [0086]     If Internet Protocol version 6 (IPv6) is used, there are sufficient IPv6 addresses. Thus, IPv6 addresses can be allocated to the local controller  410  and the sensor/actuator  412 .  
         [0087]      FIG. 10  is a diagram illustrating a signal flow for an operation for reporting an abnormal measurement in the sensor/actuator according to the present invention.  
         [0088]     Referring to  FIG. 10 , the MS  330  and the RAS/ACR  910  are located in a network, and the RAS/ACR  920 , the local controller  410 , and the sensor/actuator  412  are located in another network. A predetermined facility server  1000  may reside in a third network.  
         [0089]     To enable the RAS/ACR  910  and the local controller  410  to be able to communicate with each other at any time, they are kept in a connected state in step  940 . Likewise, the local controller  410  and the sensor/actuator  412  are kept in a connected state to enable communications between them at any time in step  945 . The following description focuses on a connected state  1005  between the MS  330  and the RAS/ACR  910  after a connection is established between them.  
         [0090]     If a measurement acquired during a measuring operation is outside a normal range, the sensor/actuator  412  sends an abnormal measurement report message containing the abnormal measurement to the local controller  410  in step  1010 . The local controller  410  forwards the abnormal measurement report message to the MS  330  in step  1020 .  
         [0091]     At the same time, the local controller  410  sends the abnormal measurement message to the facility server  1000  in step  1022 .  
         [0092]     In the case where the local controller  410  is installed in a vehicle and the sensor/actuator  412  is provided to a sensor or a switch in the vehicle, the user of the MS  330  is informed of the status of the vehicle. When the sensor senses an abnormal measurement, the abnormal measurement is reported to the server, the MS  330 , and the facility server  1000 .  
         [0093]     As described above, the present invention advantageously adds a new network or device wirelessly to a sensor network by introducing the BWA communication technology into the sensor network. That is, the new network or device can be easily installed wirelessly and the widely used IP is adopted. Therefore, the present invention offers the benefits of easy connection, fast counteraction, and easy management.  
         [0094]     While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.