An Architecture Model of Sensor Information System Based on Cloud Computing Pengfei You, Yuxing Peng National Key Laboratory for Parallel and Distributed Processing, School of Computer Science, National University of Defense Technology, China {hbypf, pengyuxing1963}@yahoo.com.cn Abstract. Sensor networks are identified as one of the most important technologies for this century. It is widely used in many applications, such as industry manufacturing and environment monitoring. One key research topic concerning it is sensor information system which aims to effectively process, manage and analyze data emanating from sensor networks so as to benefit the users. Recently, with development of sensor networks, sensor information system encounters many challenges, such as large data volumes, cost controlling, data diversity and scalability. In this paper, we propose a general architecture model for sensor information system based on cloud computing. In particular, we introduce the structure and operating mechanism of the architecture model. This architecture fully utilizes the cloud service characteristics and sensor virtualization technology to build a user-centric platform environment supplying scalable, flexible, reliable and on-demand services, which helps solve the challenges encountered by present sensor information system. Keywords: sensor networks, sensor virtualization, architecture model, cloud computing, information system. 1 Introduction Sensor networks is a key technology for many applications, including industry manufacturing, traffic surveillance, environment monitoring, health care, military sensing, air traffic control and distributed robotics [1]. One important research topic involving sensor networks is how to effectively utilize sensor data so as to benefit the users. Sensor information system aims to effectively process, manage and analyze data emanating from sensor networks, which is a critical technology for this topic. It is a distributed information system including sensor data management and sensor information management. Sensor data management is to manage and process data stream form the sensors, and sensor information management is to organize, analysis, mine and apply sensor data [2]. With increment of sensor mount and type within sensor network, and expansion of coverage area of sensor network, Scale of sensor information system is more and more huge. With diversity of sensor data source, data process manner is more and 145
more complex. It needs more and more IT resource such as high-performance sensor nodes, even mainframe and high bandwidth communication network to process, manage and store sensor data. This situation brings challenges to sensor information system, including security management of data, transparent data process model, costeffective resource deployment, and dynamic storage allocation. Cloud computing is a model for enabling on-demand access to a shared pool of IT resources that can be elastically used with low cost [3]. In this model, the capabilities of applications are exposed as services which provide dynamically scalable and often virtualized resources in web application as a service. Cloud computing brings flexibility, scalability, cost controlling and on-demand provision to applications. In particular, sensor virtualization technology enables one physical sensor to be projected as multiple virtual sensors and vice versa, and enables user applications to use sensor data in a transparent manner, which enhances resource sharing and allows virtual sensors scale up or down as needed [4, 5]. In this paper, we propose a general architecture model of sensor information system based on cloud computing. It aims to realize a general solution to effectively process sensor data and manage sensor information for various types of sensor network which may be wired or wireless, large or small, homogeneous or heterogeneous. The architecture model fully utilizes technology characteristics of cloud computing and sensor virtualization technology to build a user-centric platform environment supplying scalable, flexible, reliable and on-demand services, which help solve the challenges encountered by present sensor information system. The rest of the paper is organized as follows. In section 2, we introduce the current challenges encountered by sensor information system. In section 3, we present an architecture model of sensor information system based on cloud computing. Finally, in section 4, we conclude this paper. 2 Current Challenging Issues of Sensor Information System Presently, sensor networks develop fast. There are various types of sensor network where sensor amount is huge, bandwidth is high, coverage area is large, process task is complex and sensing data is heterogeneous, such as multimedia sensor network [6, 7]. This situation brings challenges to traditional sensor information system. Firstly, sensor information system lacks enough flexibility for processing sensor information. The sensor data type may be different or heterogeneous. When a new data type is coming, the system can not process it promptly. Secondly, sensor information system lacks effective load balancing management. For example, when applications for sensor information process reach their peak points, they still own many idle resources for a long time. At the same time, other applications such as information analyses and information storage need more resources which are hold by information process applications. This situation extremely brings down resource utilization rate and performance for the system. In addition, sensor information system lacks enough scalability for IT resource. On the one hand, due to difference for node tasks, many nodes run specific applications, and most of the time they own surplus computing and storage power. On the other 146
hand, when workloads for applications are too high, the system has to add new resources to satisfy it, which leads to extra costs. Fig. 1. An Architecture Model of Sensor Information System Based on Cloud Computing Cloud computing is a general computing paradigm, which supplies IT resources as a service to users. Cloud computing enables transparent access to resources and supplies scalability, flexibility and dynamic load balancing [3]. It has been applied in many fields [8], which is also suitable for solving those issues for sensor information system. In addition, sensor virtualization make applications for users use sensing data form physical sensors in a transparent manner, which significantly expands boundary for service capability for sensor networks. 147
3 An Architecture Model of Sensor Information System Based on Cloud Computing This proposed architecture model aims to build a general platform of sensor information system based on cloud computing, which is scalable, flexible, accesssecure, cost-effective, high-performance. It can effectively operate and process sensor data, manage, analyze and mine sensor information for various types of sensor network. 3.1 Basic Structure of the Architecture Model The architecture model applies cloud service technologies. It consists of one front-end and five application service layers as shown in Fig. 1. 1) User front-end: It is the interface for users to enter the system, including Web browser and Client application. 2) Secure access layer: It aims to control users access to the system before using the system applications. It includes Identity & Authentication unit and Access policy manager. This layer avoids malicious users access to the system, which realizes management security for the system. 3) Application layer: It is the main business application layer for the system, including Sensor data management and Sensor information management. Sensor data management is responsible for operating, processing and maintaining data emanating from virtual sensor network. Sensor information management supplies sensor information service, such as organization, analysis, mining, retrieval and visualization for sensor data. This layer presents a logical application collect of sensor information service to the users. 4) Service platform layer: It consists of core components which encapsulate various functions as specific types of services. These services are managed, monitored and provided to business applications in the higher layer in a reliable and on-demand manner. 5) Virtualization management layer: It realizes virtualization for IT resources including sensors and sensor networks from the lower layer and is responsible for managing and maintaining these virtual resources. This layer enables transparent access to physical infrastructures and dynamic resources provision to the high layer. 6) Infrastructure layer: It consists of physical IT resources, such as servers, clusters, storage equipments, computer networks and sensor networks. 3.2 Operating Mechanism of The Proposed Architecture Model Operating mechanism of the proposed architecture model mainly happens between three layers, as shown in Fig. 2. 148
Fig. 2. Operating Mechanism of The Proposed Architecture Model Virtualization management: By applying virtualization technology, such as deploying Hypervisors [9] onto each physical node, it realizes a virtual resource pool for physical resources, which can be utilized by service platform layer in a simple way. It configures and manages the virtual resource pool dynamically and realizes scalability for the system. In addition, it maintains an image repository storing various types of VM (virtual machine) images which are used to create specific VMs for the system. Moreover, it manages the templates of the virtual sensor networks and the virtual sensors and provisions the virtual sensor networks on the selected virtual server. Runtime environment for service platform: It is a runtime environment for managing, maintaining and processing specific services for application layer. It consists of some core components. Event management is responsible for detecting and processing events for application system. Service monitor is to monitor various services in the system. If some conditions are satisfied, the services will be handled by service processor component. For example, when some system status reach some thresholds, a request or return service for resources will be processed and then provision notification component is invoked to claim resources from the lower layer or give back resources to the lower layer. Thus, it realizes elastic use for resources. Operation for the entire runtime environment is adjusted by load balancing component, which can promote performance for the system. In addition, data content management supplies data service for virtual sensor networks to application layer. Sensor information system application: It is the core business application. It uses data form data service of data content management in a transparent manner. It enhances flexibility and simplifies sensor data process model. 149
4 Conclusion Sensor information system, as a distributed information system for sensor networks, is a critical technology to effectively process, manage and analyze data emanating from sensor networks. With development for sensor networks, sensor information system encounters many challenges, such as flexibility, scalability, load balancing and cost controlling issues. In this paper, we propose a general architecture model of sensor information system based on cloud computing aiming to solving above challenges. We present the structure and operating mechanism of the architecture model. By using cloud computing and sensor virtualization technologies, this architecture model builds a user-centric platform environment where IT resources are virtualized and dynamically supplied to users in a transparent manner, and sensor data is transparently used by user applications, and various applications keep an appropriate workload. It enhances scalability, flexibility, cost controlling and dynamic load balancing for sensor information system, which improves system performance effectively. However, there exist some security issues in cloud computing, which hinders users form adopting cloud computing [10]. At following work, we will research security issues for sensor information system probably brought by cloud computing. Acknowledgments. This research work is supported by National Basic Research Program of China under Grant No.2011CB302601, and National High-Tech R&D Program of China under Grant No.2011AA01A202. References 1. Chong, C.Y., Kumar, S.P.: Sensor Networks: Evolution, Opportunities, and Challenges, invited paper. Proceedings of the IEEE, 91, 1247--1256 (2003) 2. Thuraisingham, B.: Secure sensor information management and mining. IEEE Signal Processing Magazine, 21, 14--19 (2004) 3. Mell, P., Grance, T.: The NIST definition of Cloud Computing. Technical report, National Institute of Standards and Technology (2011) 4. Yuriyama, M., Kushida, T.: Sensor-Cloud Infrastructure-Physical Sensor Management with Virtualized Sensors on Cloud Computing. In 13th International Conference on Network- Based Information System, 1--8 (2010) 5. Yuriyama, M., Kushida, T.: Integrated Cloud Computing Environment with IT Resources and Sensor Devices. Intel. J. of Space-Based and Situated Computing, 1, 163--173 (2011) 6. Sharif, A., Potdar, V., Chang, E.: Wireless Multimedia Sensor networks: A Survey. In: 7th IEEE International Conference on Industrial Informatics, pp. 606 613 (2009) 7. Charfi, Y., Wakamiya, N., Murata, M.: Challenging Issues in Visual Sensor Networks. IEEE Wireless Comm, 16, 44--99 (2009) 8. Wang, J., Abid, H., Lee, S., Shu, L., Xia, F.: A Secured Health Care Application Architecture for Cyber-Physical Systems. J. C. E. A. I., 13, 101--108 (2011) 9. Mauch, V., Kunze, M., Hillenbrand, M.: High Performance Cloud Computing. F. G. C. S. (2012) 10. You, P., Peng, Y.: Security Issues and Solutions in Cloud Computing. In IEEE ICDCS Workshops, unpublished (2012) 150