Research on Key Issues of Combination of Wireless Sensor Network and Grid
Research on Key Issues of Combination of Wireless Sensor Network and Grid Advances in technologies such as microelectronics and embedded systems are driving the rapid development of wireless sensor network technologies. Wireless sensor networks are now used in many fields such as environmental and biological monitoring, industrial monitoring, and military security monitoring. Through the large number of sensor nodes arranged in the monitoring area, the physical world can be precisely measured, the quantity and quality of real-world data required by the application can be improved, and the monitoring cost can be reduced. The wireless sensor network has become a new computing platform that can seamlessly connect the digital world and the physical world; it consists of a series of sensor nodes, each of which has environmental awareness, data processing, and wireless communication capabilities. The sensor node has the characteristics of battery power supply, limited computing and storage capacity, and low communication bandwidth, which limits its processing and utilization of the obtained data [1]. Now, the grid technology with the characteristics of high-speed computing power, huge storage capacity and high-speed communication bandwidth has become a standard way to solve large-scale distributed and heterogeneous resource sharing in a dynamic virtual community. Combining wireless sensor networks and grids can effectively make up for wireless sensor networks, and has the following advantages: 2. The key issue of the combination of wireless sensor network and grid Wireless sensor networks and grids are two very different networks, both of which are different in physical layer, communication protocol, and application protocol. The problems such as network connection, scalability, and task scheduling encountered in the process of combining wireless sensor networks and grids need to be solved using the combination framework proposed in this paper. (1) Wireless sensor network access layer: The main role of this layer is to seamlessly access multiple wireless sensor networks, abstract the wireless sensor network, and make the upper layer see a consistent data layer. This layer mainly completes tasks such as network protocol conversion, grid API mapping, multi-wireless sensor network access, security assurance, and task robustness. High Brightness Open Frame Monitor High Brightness Open Frame Monitor,Open Frame Monitor,High Brightness Embedded Lcd Monitor,Embedded Open Frame Lcd Monitor Shenzhen Risingstar Outdoor High Light LCD Co.Ltd , https://www.risingstarlcd.com
(1) A large amount of data sensed by the wireless sensor network can be processed by grid.
The computing and storage resources possessed by the grid can process, analyze and store the large amount of data collected by the wireless sensor network.
(2) The data from a wireless sensor network can be used by multiple grid applications simultaneously.
The data from the same wireless sensor network can be used by multiple applications through the grid platform at the same time, the use of sensor data is more convenient, and the data utilization rate is increased at the same time.
(3) Using the grid, new knowledge of wireless sensor network data can be obtained.
Data mining, data fusion, distributed database and other technologies can be used to process the data in the grid to obtain new knowledge of sensor data.
1. Related work
HourGlass [2] is a combination of grid and wireless sensor network. HourGlass is mainly composed of three parts: data collection network (DCN), sensor access point (SEP), and application access point (AEP). DCN consists of an Internet-connected system that can discover, filter, and query multiple wireless sensor networks. SEP can map the data requirements of the application to operations on the underlying wireless sensor network, or route the data on the wireless sensor network to the data collection network (DCN). AEP is a connection system for applications to connect to DCN, and it maps application requests to DCN-based services for processing.
SensorGrid [3] [4] is a composite system composed of wireless sensor network and grid. SensorGrid adopts a distributed network structure, which is composed of sensor nodes, middle layer and decision making layer. The system mainly considers the problems of distributed data fusion, distributed processing, network collaboration, etc. It can carry out data fusion, transaction monitoring and classification, distributed decision making and other work.
(1) Different network connection problems The interconnection between sensor nodes in a wireless sensor network is through a low-bandwidth, high-latency and unreliable wireless network. The wireless connection between sensor nodes will cause wireless communication due to the effects of environmental noise and signal attenuation Interruption; the interconnection of various devices in the grid is through a fast and reliable wired network. In the combined framework, it is necessary to solve the problem of unpredictable network interruption and communication delay in wireless communication of sensor nodes.
(2) Protocol mapping of wireless sensor network and grid The standard Internet protocol used in grid communication, such as TCP / IP, HTTP, etc. Wireless sensor network communication usually uses private protocol, especially MAC protocol and wireless routing protocol are mostly private protocols. Due to the limited computing and storage capabilities of sensor nodes, and the inability to use Internet protocols, it is necessary to effectively map the network communication protocols used in the grid to the nodes of the wireless sensor network in the combined framework.
In addition, the grid's OGSA standard is based on Web Service, which uses technologies such as XML, SOAP, and WSDL. It is unrealistic for sensor nodes to package sensor data into XML format and publish it as a grid service. It is necessary to map the sensor data into grid service in conjunction with the framework.
(3) The scalability combination framework needs to dynamically add the wireless sensor network to the grid without changing the overall structure. It needs to be able to connect multiple wireless sensor networks simultaneously, and can be easily integrated with grid computing and storage resources, so that users can transparently use multiple wireless sensor networks.
(4) Energy management sensor nodes are powered by batteries and usually cannot be replenished. Energy management is a very important issue in wireless sensor networks. From the perspective of the combined framework, the availability of sensor nodes depends not only on their current load status, but also on their energy surplus. The combined framework should be able to provide adaptive energy management services, so that applications using wireless sensor networks can find a balance between sensor node operation and power usage.
(5) Task scheduling Task scheduling of sensor nodes in wireless sensor networks should consider energy consumption and available sensor resources. At the same time, the wireless sensor network is a data-centric network. When scheduling tasks, it is also very important to effectively use the sensor data collected by the sensors. When there are multiple wireless sensor networks in the combined framework at the same time, it is required that the scheduling process can make full use of multiple types of data.
(6) System security The data sensed by the wireless sensor network is often very important and requires confidentiality, and does not allow any data theft and malicious modification. Grid resources also require authenticated individuals and service providers to be able to access. In the grid, through the authentication and authorization mechanism to ensure the legal identity of visitors, to achieve secure access to grid resources. Wireless sensor networks use node authentication, sensor data encryption, and secure MAC protocols to ensure power saving and effective security of sensor data. In order to ensure the security of grid and wireless sensor network at the same time, it is necessary to combine grid security technology and wireless sensor network security technology to ensure the security of the entire system.
(7) Robust sensor nodes use battery power and use unreliable wireless communication network communication, which may cause the failure of the sensing task running on the sensor nodes. In order to prevent the failure of the sensing task on the sensor node, the combined framework should support task replication and migration. In this way, if some sensor nodes fail, the sensing task can also be quickly moved from the failed sensor node to the normal node. If there are enough sensing resources, the sensing task can also be copied. In this way, the failure of some nodes will not affect the execution of the entire sensing task. Finally, if the sensing task is interrupted, after the system is restored, the sensing task should be able to restart from where it was interrupted. (8) Service quality Service quality can determine whether the system can provide effective sensing resources and services. Through the QoS parameters, the sensor nodes, storage space, communication bandwidth, power consumption and other indicators used by the grid sensing task can be specified. Through the use of these indicators, the robustness of the sensing task can be increased, and the effects of node failure and communication interruption can be avoided. Combined with the framework to meet the needs of different QoS, the QoS requirements specified by the upper layer are mapped to the underlying QoS parameters. When sensing tasks require multiple different sensor resources, in order to achieve the required QoS, the sensor resources need to be reserved.
3. Wireless sensor network and grid combination framework The wireless sensor network and grid combination framework can enable multiple wireless sensor networks to access the grid and provide unified grid services. The framework is mainly composed of three layers: wireless sensor network access layer, task management layer and service management layer. The entire system framework is shown in Figure 1. 
(2) Task management layer: the main role of this layer is the reasonable scheduling of multi-data fusion tasks. This layer mainly completes tasks such as rational allocation of data processing tasks and rational scheduling of multi-sensor tasks.
(3) Service management layer: The main role of this layer is the management of wireless sensor networks and the formation and management of wireless sensor network services. This layer mainly completes tasks such as wireless sensor network energy management and service quality control.
4. Conclusion The combination of wireless sensor network and grid can effectively make up for the problem of insufficient energy-saving data processing capability of sensors. This paper proposes a combination framework to realize the combination of wireless sensor networks and grids, and discusses the key issues that need to be resolved during the combination process. The combination framework can effectively solve the problems of network interconnection and task scheduling, seamlessly integrate wireless sensor networks and grids, and increase the processing capacity of sensor data. However, the current combination framework has some shortcomings, such as not considering the special processing of mobile sensor nodes, and unable to improve the scheduling method of sensor nodes. This is also a place that needs to be improved in the future. The author's innovation:
This paper proposes a combined framework for solving the combination of wireless sensor networks and grids, and analyzes the problems and solutions in the process of building a combined framework. The combination framework can effectively solve the problems of network interconnection and task scheduling, seamlessly integrate wireless sensor networks and grids, and increase the processing capacity of sensor data.