The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
To improve the localization accuracy of wireless sensor networks (WSNs) node for underground tunnel monitoring, we propose a method to improve the localization accuracy of Received Signal Strength Indication by using the anchor node selection mechanism, which is based on the three-dimensional space characteristics of the mine and the choice of the wireless communication frequency. Firstly, we sort...
In order to make the distributed location of wireless node visible, this paper has studied the location methods based on WSN. The weighted-centroid localization algorithm based on fusion ranging of RSSI and TOF has been proposed, which is proved effective according to the simulation results. The algorithm provides a method to study the automatic location identification and geographic information collection...
The research works of thirteen langasite-type crystals and YCOB crystal grown in SICCAS since 2002 were reported. Their piezoelectric properties at room temperature and high temperature up to 900°C were characterized in two cooperation universities and the product applications of SAW sensors and accelerometers in a German company were summarized here.
The positioning technology is one of the most important technologies in the wireless sensor network. The paper describes the current international positioning on several existing technologies, including the based ranging RSSI, TOA, TDOA, etc. and non-centroid algorithm based on distance, Amorphous algorithm, APIT algorithm and so on. Dv_Hop algorithm is a distributed localization algorithm based on...
Apart from static deployments, sensor nodes in Wireless Sensor Networks (WSNs) are unaware of their location information. In order to estimate their actual or relative positions with respect to other nodes, they are required to self-localize themselves by collecting information from their environment. However, due to the high dynamism and the noise introduced by the WSN environment, self-localization...
Localization of persons or equipment in ad-hoc scenarios, e.g., after an earthquake still poses many challenges. The popular received signal strength (RSS) based localization methods usually cannot provide the needed accuracy especially if sensor equipment or tools are to be localized in a static environment with non line of sight conditions. On the other hand, time-of-flight (ToF) measurements have...
Several ways to estimate the position of a Wireless-Sensor-Network (WSN) node have been discussed in the past years. Unlike in outdoor solutions where the Global Positioning System (GPS) could be used in most applications, a general solution for indoor usage has not been found. The few existing indoor localization solutions on the market are highly specialized and rely on infrastructure or on very...
Many localization algorithms and systems have been developed by means of wireless sensor networks for both indoor and outdoor environments. To achieve higher localization accuracy, extra hardware equipments are utilized by most of the existing localization algorithms, which increase the cost and greatly limit the range of location-based applications. In this paper we present a method which can effectively...
Wireless ad-hoc sensor networks are typically deployed randomly in space to gather information about the physical world. In these spatially random sensor networks, one of the fundamental problems is precise node localization along with the key requirement to keep node cost at minimum. Existing radio interferometry-based node localization techniques achieve cm resolution using only low-cost radio chips...
Distance measurement between nodes in wireless sensor networks is a prerequisite for a variety of applications and algorithms. However, special hardware allowing such measurements is expensive, especially if dealing with hundreds or thousands of nodes. Fekete et al. presented an approach on distance estimation based on only the neighborhood information available to all nodes in the network. We improve...
Localization technology is the important supporting technology in wireless sensor networks. Positioning precision is largely determined by ranging precision in the localization technology based on the distance. Traditional RSSI ranging method exists some problems of path loss model complex, serious signal concussion caused by environmental changes, which leads to ranging error and so on. According...
Distance measurement based on RSSI, featuring low communication overhead and low complexity, is widely applied in the range-based localization of the wireless sensor networks. We first analyze the theory of distance measurement based on RSSI and the influence of environment on RSSI, and then we propose three experimental data processing methods. After using the ZigBee-based hardware platform to test...
Localization is the process of finding the geometric locations of wireless sensor nodes according to some real or virtual coordinate system. It is an important task when direct measurements of the wireless sensor locations are not available. From the various techniques evolved in localizing sensor nodes, one approach is to use the received signal strength to predict the location of unknown sensing...
Developing efficient localization techniques to allow sensors to estimate their positions has been a hot research topic for long time. Sensory readings are almost meaningless if they are not associated with the locations in which these readings were taken. Getting location information through recording positions manually or through an expensive GPS chip are not valid options for sensor networks. We...
We demonstrate an anchor-free mobile node localization system using Ymote, which is equipped with the IEEE 802.15.4a RF module based on chirp spread spectrum (CSS) technology. In contrast to conventional centralized systems, our system is fully distributed, hence scalable, and enables self-positioning in anchor-free environment. The localization system is implemented on the RETOS operating system.
Wireless sensor networks are shaping many activities in our society as they have become the epitome of pervasive technology. In Many Circumstances, it is useful or even necessary for a node in a wireless sensor network to be aware of its location in the physical world. For example tracking or event detection functions are not particularly useful if the WSN cannot provide any information where an event...
Existing localization approaches are divided into two groups: range-based and range-free. The range-free schemes often suffer from poor accuracy and low scalability, while the range-based localization approaches heavily depend on extra hardware capabilities or rely on the absolute RSSI (received signal strength indicator) values, far from practical. In this work, we propose a mobile-assisted localization...
Transmission power control to save energy has been described in many studies to capture their efficiency. These previous methods, however, are too complicated, costing much communication, calculation, and require special hardware. Our simple method uses only one flooding to complete setting of all the nodes. The power is decided according to the hops from every node to the sink. The nodes with the...
Making distance measurements with RSS can be challenging in indoor environments. The effect of multipath and shadowing introduces ambiguity into the readings, leading to a range of distances that can be inferred from a single measurement. This contribution highlights the frequency dependancy of these effects. Lower and upper bounding constraints are introduced to achieve an practical operational range...
The off-line training RSSI localization algorithm is only fit to the position where it has been trained before and whenever the condition of the environment changes, the program in the hardware must be reprogrammed, so the algorithm has a poor adaptability under different environments and leads to a certain limitation to the applications in some projects. Combined with the rough-precision TOA, a new...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.