Categories and Subject Descriptors H.4.2 [Types of Systems]: Decision support

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1 An Asset Management System Based on RFID, WebGIS and SMS Shengguang Meng, Wei Chen, Gang Liu, Shitong Wang, Liu Wenyin Department of Computer Science, City University of Hong Kong Hong Kong SAR, China ABSTRACT In this paper, we propose an asset management system using technologies of Radio Frequency Identification (RFID), Web Geographic Information System (WebGIS) and Short Message Service (SMS) for intelligent management of assets. The proposed method tracks and monitors the changes of locations of the assets and shows their statuses on a geographical map, preventing the loss of assets due to unclear reasons. The movement of assets can be automatically identified using the RFID technique. The corresponding data are transferred by the GSM module in real time, enabling the spatial information of assets to be displayed on an electronic geographical map using WebGIS. The proposed method also facilitates automated notification of asset movement and malfunction alarm through SMS. Preliminary experiments show that the proposed method can improve information availability of assets and reduce asset management cost dramatically. Categories and Subject Descriptors H.4.2 [Types of Systems]: Decision support General Terms Management Keywords Asset management, RFID, WebGIS, SMS, wireless, spatial database, information retrieval 1. INTRODUCTION Asset management has long been considered as an important issue in enterprise organizations. However, automated asset management has still not been appropriately supported by existing IT systems. Assets are not managed individually. Information about location, status and usage is not accurate or lacking. This may cause delays in industrial operations, inefficient use or excess inventory of costly assets, and may even lead to asset damage or accidents. In order to solve those problems, we propose a method for asset management based on RFID, WebGIS and SMS technologies. The proposed method combines the techniques of RFID, WebGIS and SMS. RFID is used to automate tracking and monitoring the movements of assets that are to be controlled in real time. SMS is used for automated transferring of asset movement information in a distributed environment where the deployment of cable network is not feasible. The employment of WebGIS technique facilitates the dynamic visual representation of the spatial information of the asset distribution on an electronic map. We carry out preliminary experiments based on a real application of enterprise asset management over ten months to prove its efficiency and feasibility. The results of the experiments show good user experience and significant cost decrease of asset management. The rest of this paper is organized as follows. Section 2 presents related work. Section 3 introduces the method that combines RFID with WEBGIS and SMS technologies for intelligent asset management. Preliminary experiments with a real application are presented in Section 4 for evaluation of the system. We conclude our work in Section RELATED WORK RFID is a technology which provides non-contact, non-line-ofsight wireless data communication between devices in a system. It consists of three basic components: antenna, RFID reader, and RFID tag, as shown in Figure 1. The antenna emits radio signals to activate the tag and read or write data to it. Often, the antenna is packaged with the RFID reader to become an interrogator. The RFID reader is the main controller of the system for data acquisition and communication. The interrogator emits radio waves in ranges of anywhere from a few inches to 100 feet or more, depending on its power output. When a RFID tag passes through the electromagnetic zone, it detects the interrogator s activation signal. The interrogator will then decode the data encoded in the tag and process it. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Figure 1. Illustration of RFID working mechanism RFID has been widely used in the fields of manufacture, traffic, logistics, etc. Especially, several pieces of work have been done for applying RFID techniques to asset management. Mark et al. 82

2 propose a RFID-based tagging and tracking method that supports total asset visibility for the military [1]. It can be used to provide programs such as FCS with persistent knowledge of the location and status of every asset, thus providing commanders the assurance to verify logistics and plan missions. Barber and Tsibertzopoulos investigate the features of the new UHF RFID standard and their implications for asset management [2]. Of these features, tag memory, security techniques, operational modes, communication methods, global applicability, and other expected implementation specific improvements are covered. The improvements that the features bring to asset management are also mentioned. A passive RFID management method is proposed by Hakim et al. and is implemented in Hartford Hospital, Connecticut, for asset tracking [3]. The technique is employed to monitor Telemetry Transmitters (TT) in order to prevent losing them. The work exploits the capabilities of passive RFID technology to determine the location of TTs as they pass through certain key spots in the hospital, and shows that the asset monitoring system is able to communicate with the hospital equipment management database in order to get queries or send other necessary commands. WebGIS is a new technology which combines the Internet and GIS. End users can search and analyze the GIS data intuitively on the Internet using browsers. In our solution, we adopt the MapInfo MapXtreme component which is a map application platform and can provide WebGIS data exchange and management services. MapXtreme provides an approach to parallel access to database for multiple users within a short time and return a user request to the client browser by Web service. The advantages of WebGIS are the visual data sustaining to providing assistant decision for users, coexisting of words and images and visualization. The adoption of WebGIS will provide a new perspective for the management method of the asset management system. This solution has a very high value in popularization and application. Luo et al. proposed a framework to provide a new model for WebGIS services in a network environment [4]. This framework consists of three layers: user layer, application layer and WebGIS service layer. The user layer supports users to access WebGIS services via different network environment; the application layer represents WebGIS applications constructed by different organizations or companies, which integrate GIS services to solve some domain-oriented problems; WebGIS service layer provides different GIS services. The WebGIS service layer is a multi-agent system, where WebGIS services are implemented as agents to match the use of different users/applications. Short message service (SMS) is a service for sending short messages to mobile devices, including cell phones, smart phones and PDAs. SMS has been perfect in many fields, such as remote monitor, data collection, and wireless alarm, due to its low cost, high speed, high reliability and security etc. Kwon et al. develop a blood glucose management system using the Internet and SMS which can lessen the social economic burden and materialize an individualized diabetes mellitus management [5]. Participants can send their self-measured blood glucose levels, medication and its dosages, amount of meal, and degree of exercise to their health providers in this specialized diabetes management system. The health providers consisting of endocrinology specialists, dietitians, and nurses can then send recommendations for individualized diabetes management according to the data received accordingly. This diabetic patient management system can be seen as a new tool for communication between health care providers and patients. Existing RFID-based asset management or tracking systems transfer data using the Internet or a local area network. However, those systems may not be suitable for the assets with the following characteristics: (a) distributed in different locations, (b) located in a limited area, (c) no network environment is available or it is costly to establish network environment. For example, for assets in base stations of mobile communication companies, some of them are located on top of a building, and some of them are located on the mountainside or mountaintop. Hence, we also propose using WebGIS and SMS technologies to such situations. 3. THE PROPOSED ASSET MANAGEMENT SYSTEM 3.1 Overview The proposed asset management method is mainly for large-scale companies whose distributions of assets are extensive and dispersive, such as electricity companies and mobile communication ones. The proposed method utilizes RFID technology and integrated wireless data transfer technology to perform automated management for access, transfer, maintenance, and stand-down of assets. It also utilizes advanced Web-based GIS technology to implement the asset managing geographically. Users are able to search and display several kinds of information of assets on an electronic geographical map, such as their identities, spatial information, statistical information, usage status, transfer record, maintenance record, malfunction information and so on. The SMS technology is also utilized to inform administrators of base stations (which are used in this paper to refer to the buildings or limited areas to host the assets) about asset transfer and asset working status in real time. 3.2 System Architecture Figure 2. Architecture of the proposed system Figure 2 shows the architecture of the proposed system. From the figure we can see that the system is distributed over a local area network. It consists of several subsystems that will be introduced in the following sections. 83

3 3.2.1 Asset Automatic-Identification Subsystem (AAIS) This subsystem consists of three basic components: a RFID reader, an antenna that is installed at the entrance of the base station, and several RFID tags that are attached to the surface of the assets. The RFID reader emits radio-frequency signals using the antenna for communication with the RFID enabled tags. A GSM module is integrated into the RFID reader for sending and receiving SMS. When assets enter or leave the base station, the RFID reader can read their data from the tags attached to them. The asset data will be sent to an application server in real time by SMS. The communication between AAIS and the application server ends when a confirmation SMS is received from the application server Application Server This subsystem consists of an SMS service module and a MapXtreme module. SMS service module includes the following functions: (a) receiving all SMSs from RFID readers in base stations, (b) sending a confirmation SMS to the RFID reader when a message is received and (c) sending a SMS to the RFID reader of a base station to inspect its working status. (When receiving the confirmation SMS from a base station, we are sure that the corresponding RFID reader is working normally), and (d) analyzing from which RFID reader an incoming SMS comes. In our proposed method, there is a Subscriber Identity Module (SIM) card applied to the GSM module which is integrated into a RFID reader that holds personal identity information, cell phone number, phone book, text messages and other related data. The SMS source can be identified according to the cell phone number of the SIM card. In this way, the RFID readers can be managed individually. The content of the message is converted to an appropriate format for storage in databases in this module. The MapXtreme module is an application module based on WebGIS technology. It can provide a visual representation to show the relevant spatial information of the asset management system. When a user query of spatial data is sent to the Web server in the system from the user s browser, the Web server transfers the related parameters to MapXtreme in the application server. MapXtreme queries the corresponding map data from the GIS database and the asset data from the basic database. Afterward, the query result is returned from the application server to the Web server and then rendered on the user s browser. Figure 3. Operating mode of MapXtreme Database Management System (DMS) All data that are used in the proposed method are stored in a relational database, including basic data, spatial data, and attribute data in this system so that data storage and management can be separated from the application logic. The database management subsystem mainly consists of the following two databases. (a) Basic Database The Basic Database is mainly used to store data about base stations, assets, and SMSs, etc. It provides the functions of data storage, searching, updating and retrieval. Users can query the data they need from the Basic Database expediently, accurately and in time. (b) GIS Database GIS Database is a dataset to describe the geographical characteristics of an area that is to be controlled by the system. It does not only have the attribute data of geographical factors that are similar to the data properties of general databases but also a large volume of spatial data which describe the spatial distribution of geographical factors. There is an indivisible relation between the attribute data and the spatial data. The MapXtreme system can adopt either file strategy or spatial data strategy to manage GIS data. In the proposed method, we adopt the spatial data strategy to manage the GIS data. Spatial data strategy can perform integrated management of spatial data and attribute data by utilizing spatial databases. This can take the advantages of current large business database systems to implement distributed structures and multiuser concurrent visiting functions. Spatial database is a hot research topic nowadays in GIS field. We adopt the OracleSpatial to manage the attribute data and spatial data in the system Background Asset Management Subsystem (BAMS) The BAMS subsystem works in a browser/server (B/S) mode. The main modules of this subsystem are introduced as follows. Asset Data Maintenance This module takes the charge of maintaining the entire asset database. System administrators can add or modify asset information, such as asset name, asset number, asset type, manufacturer, production time, specification, purchase time and so on. The relations between RFID tags and asset entities are established in this module. Asset Automated Management This module utilizes RFID technology and wireless data transfer technology to implement asset data automated gathering and processing so that the asset management can be automated. The detailed implementation is further discussed in Section 3.3. WebGIS Module This module utilizes the advanced Web-based GIS technology to implement the asset management with geographic information integrated. Users can search and display spatial information of assets on the electronic geographical map, such as basic information, location information, statistic information, usage status, transferring record, maintenance record, and malfunction information and so on. The system adopts MapInfo MapXtreme component to implement the WebGIS functions. MapXtreme can read and display map data of GIS databases. On the client-side, there are many functions on the electronic geographical map, such as map search, map visualization, layer control, zoom in/out, roam, creation of the special subject map, etc. SMS Notifications and Alarms 84

4 The functions of SMS notifications or alarms can be customized in BAMS. For example, the system can be configured so that a SMS is sent to the administrators of a base station whenever an asset moves in or out of it. It is also possible for the system to send an alarm SMS to the corresponding maintainers of a base station to repair it as soon as possible when a RFID reader or a GSM module is not usable. 3.3 Automated Asset Transfer Process An Automated Asset Transfer Process (AATP) module is proposed that combines RFID technology with WebGIS and SMS technology in the system. AATP is the process that an asset is transferred from a base station to another base station. An example is presented in which one asset is transferred from base station A to base station B. The state change process of this asset is shown in Figure 4. Figure 4. The transformation of the status of an asset The steps of AATP are described as follows. 1. The state is normal when the asset works normally in base station A. 2. The RFID reader in A reads the asset data from the tag attached on the asset when the asset is moved out of A. The removed asset data are then uploaded to the application server through the GSM module. The application server then updates the removed asset data to the database system. 3. The BAMS stores the location and the time of the movement of the removed asset automatically and changes the asset state to pending condition. It then sends a notification SMS about the removal of the asset to the administrators of A. 4. The RFID reader in B reads the asset data from the tag attached on the asset when the asset enters the base station B. The information of the incoming asset is then uploaded to the application server through the GSM module. The application server then updates the incoming asset data to the database system. 5. The BAMS stores the location and time of the movement of the incoming asset automatically and changes the asset state to normal condition. It then sends a notification SMS about the incoming asset information to the administrators of the base station B. 6. The BAMS saves all the data of the incoming asset to the base station B and records the asset transfer accordingly. After finishing an asset transfer, the administrators of base station A and B will get SMSs about the related information of the asset transfer. The asset transfer information is updated to the database system automatically. The asset transfer information can also be shown on the WebGIS interface in BAMS, as shown in Figure 5. Figure 5. WebGIS Interface In Figure 5, a big blue point icon represents a base station. Users can see the information window of this base station by clicking on it. The window shows basic data and statistic data of the base station, such as longitude (LON), latitude (LAT), entering asset sum on a particular day, and so on. A big blue point with an outgoing edge in the figure indicates that new assets have left this base station recently. Users can get the information of the removed asset by clicking on this icon. After clicking, the icon will be hidden in the map until new assets are moved out of the base station in the future, or if there is any other information change in this station. A big blue point with an incoming edge in the figure indicates that assets have entered this base station recently. Users can get the information of the incoming asset by clicking on this icon. After clicking, the icon will be hidden in the map until assets enter the base station next time in the future, or if there is any other information change in this station. 4. EXPERIMENT RESULTS A prototype system based on J2EE architecture is developed for the evaluation experiments of the proposed method. We cooperate with the subordinate company of China Mobile Communications Corporation for the implementation of the asset management on a real application of asset management in mobile base stations. The system has been deployed to 30 base stations in the company. The 30 base stations are distributed in different towns of a city. 4.1 Experiment Settings Only a browse is needed to be installed on a client-side machine. The application server uses the operating system of Windows 2003 Server and has MapXtreme for Java installed for supporting WebGIS functions. The Web server uses the operating system of Windows 2003 Server and has Tomcat5.0 and Sun JDK- 1_5_0_07 set up for supporting JSP programs. An Oracle9i database is employed to manage basic and GIS data. 4.2 Experiment Results The asset information of the 30 base stations is input into the database system. The automated asset identification system starts to gather the asset data of the 30 base stations afterward, such as the asset movement information, the working status of RFID readers and GSM modules, and so on. Those data are submitted to the application server using SMS. The application server processes the SMS messages and updates the database system accordingly. Those data can be queried and represented on the WebGIS interface. The system can also send notification SMS 85

5 messages to the administrators of the base station about the movement and status of the assets. Figure 6 shows a partial list of alarm/notification SMS of the system. Figure 6. Alarm SMS list The experiment results show that the process time of asset movements is usually less than 4 seconds and all data are updated correctly in the entire process. Compared with traditional asset management methods, this system not only enhances user experience by using WebGIS and SMS technologies, but also greatly save the cost of asset management. The system has been up running for ten months. It benefits the mobile communication company in the following aspects: (a) reducing the cost of purchasing repetitive assets by 42%; (b) reducing asset audit cost by 75%; (c) reducing asset lost rate by 45%; (d) increasing the asset usage rate by 35 percent; (e) prolonging average asset usage life by 10%. 5. CONCLUSION AND FUTURE WORK In this paper we propose a novel method for asset management in enterprise organizations using RFID, WebGIS and SMS technologies. The main merits of the method are as follows. (a) The proposed method can obtain the movement information of assets automatically and transfer it to the application server by integrating RFID technology with GSM wireless module. The whole process is completely automatic, needing no manual intervention. Thus it can avoid data distortion problem due to factitious factors during collecting and inputting the asset data. (b) The method utilizes the advanced Web-based GIS technology. Users can search and view statistics of the spatial distribution and other related information of the assets using electronic geography map. It greatly enhances the system maneuverability and user experience. (c) It utilizes the SMS technology to inform administrators of base stations about asset transfer information and asset working status in real time. This method performs highly efficient monitoring of assets and therefore enhances their management in our preliminary experiments with a real asset management application. Future enhancements of the system may include the following. (a) The current speed of sending SMS is somewhat slow. It sometimes takes about four minutes to receive a SMS message. We shall investigate the possibilities of improving the speed of wireless data transfer so that the system processing speed can be improved. (b) We shall employ an additional subsystem in the proposed method to enhance the system security. 6. ACKNOWLEDGMENTS The work described in this paper was fully supported by a grant from the Research Grants Council of the Hong Kong SAR, China [Project No. CityU ], the China Semantic Grid Research Plan (National Grand Fundamental Research 973 Program, Project no. 2003CB317002). 7. REFERENCES [1] Buckner, M., Crutcher, R., Moore, M., Whitus, B.: Miclog rfid tag program enables total asset visibility. Proc. MILCOM 2002, vol.2, pp , 7-10 Oct [2] Barber, G., Tsibertzopoulos, E.: An analysis of using epcglobal class-1 generation-2 rfid technology for wireless asset management. Proc. IEEE Military Communications Conference, 2005 (MILCOM 2005), vol. 1, pp , Oct [3] Hakim, H., Renouf, R., Enderle, J.: Passive rfid asset monitoring system in hospital environments. Proc. 32nd Annual Northeast Bioengineering Conference, pp , [4] Yingwei, L., Xiaolin, W., Zhuoqun, X.: Design of a framework for multi-user/application oriented webgis services. Proc.. International Conference on Computer Networks and Mobile Computing, pp , [5] Kwon, HS., et al.: Development of web-based diabetic patient management system using short message service (SMS). Diabetes Res Clin Pract. 66(suppl 1):S133 7, Dec