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Accurate timing is often required for the intelligent electronic devices (IEDs) used in transmission substations. A common method of achieving this is direct connection of a device to a local global positioning system (GPS) receiver and the use of its one-pulse-per-second synchronizing signal and the IRIG-B coded message. However, concerns about GPS reliability are encouraging the use of timing systems...
Increasing safety and environmental requirements of modern cities transport infrastructure rely on progress in the area of intelligent transportation systems and presume the widespread use of V2V and V2I communication to implement the user-oriented cloud services like persistent Internet access, traffic accidents information and routing capabilities. Because of the noticeable time delay in vehicles...
Internet services rely on communication networks to serve billions of end-users worldwide. Metrology platforms are used to assess the Quality of Service of such networks. This work reviews and classifies the existing metrology equipment and methods. In particular, we provide elements of comparison between different packet capture techniques and clock synchronisation methods, two essential building...
This paper reports a study and practical evaluation of two different clock synchronization methods for distributed measurement and control nodes based on Linux Single Board Computers (SBCs) with ARM processors and communicating through a TCP/IP wide area network. First the Network Time Protocol (NTP) is configured and evaluated in different network scenarios. The second solution is a specific development...
In order to satisfy the requirements of the government officials of small towns for handling official business on the spot in country area. A small town e-Government system based on Wireless communications technology, Global Positioning System (GPS) technology and Embedded Development Technology was developed. The system can run at the mobile equipments, such as Personal Data Assistant (PDA), intelligent...
When adapting existing table games for the mobile setting, there is a choice of either keeping the round-based approach of such games or giving it up and optionally replacing it with additional “magical” features only available for the location-based version of the game. Based on our experience in building a hide and seek game using both approaches independently in two research groups, we compare...
This paper introduces the Construction of the Clock Synchronization System in Management Information Domain of Power Grid. Along with the development of the SMART GRID, Clock synchronization system plays a more and more important roles for information system. The Synchronous accuracy needed by management information domain is lower than 1 second. The network time protocol (NTP) satisfies the needs...
In today's world of control systems there are various devices such as computers, Programmable Logic Controllers (PLCs) and Intelligent Electronic Devices (IEDs) that need accurate time for working properly. In order to maintain a precise time in those time needing systems, the time synchronization idea has been developed. In Modern control systems like Distributed Control System (DCS) and Field control...
Nowadays, accurate and reliable time is an essential requirement in computer network based systems. To fulfill this necessity, time synchronization idea has been developed. Meanwhile in some cases, reliable time is so vital, therefore a redundant structure can be used. In this paper, a time synchronization system is investigated by designing and implementing a time synchronization board capable of...
In today's world of computer based control systems, there are so many applications which require precise timing. In order to maintain a precise time in those time needing systems, the time synchronization idea has been developed. Today there are many Commercial Products doing this job. In this paper we are trying to build a simple and Low Cost GPS Based Computer Network Time Synchronization Board,...
This paper describes a TDOA-based positioning system by means of ultra-wideband impulse radio (UWB-IR). The system consists of three reference nodes and a location server. One of the reference nodes transmits an impulse signal to other reference nodes for synchronizing them immediately after receiving an impulse signal sent from a target node. Thus, no additional component for the synchronization...
In peer-to-peer (P2P) applications, a group of multiple peer processes (peers) are required to cooperate with each other. In this paper, we discuss a heterogeneous hybrid time group communication (HHT) protocol which takes advantage of the linear time (LT) and physical time (PT) to causally order messages in a scalable heterogeneous group. It depends on accuracy of each physical clock and minimum...
Online communication offers organizations greater efficiency. However, online processes increase the threat level during message transfer. This necessitates researchers to develop and improve security protocols in order to enhance the security of communication lines. There are many evaluation tools such as BAN Logic to evaluate how secure authentication protocols' messages are. Despite the evaluation...
In peer-to-peer (P2P) applications, a group of multiple peer processes (peers) are required to cooperate with each other in a distributed manner. Messages sent by peers have to be causally delivered to every peer in a group. Due to the message overhead O(n) for the number n of peers, the vector clock cannot be used to causally deliver messages in a scalable group. On the other hand, the linear clock...
In distributed peer-to-peer (P2P) applications, a group of multiple peer processes (peers) are required to cooperate with each other. Messages sent by peers have to be causally delivered. In this paper, we discuss a scalable group communication protocol for a group of multiple peers in P2P overlay networks. Due to the message overhead O(n) for the number n of peers, the vector clock cannot be used...
A wired testbed's usefulness for wireless research hinges on its ability to faithfully reproduce the wireless medium. One of the key properties of a wireless medium is its broadcast nature. Wireless broadcast behavior is used in applications such as cell phone and satellite networks to disseminate the same data to multiple users as well as perform time synchronization. In this paper, we investigate...
This paper presents an Agent-based Timing-Sync Algorithm (ATSA) for sensor networks that aims at providing network-wide time synchronization in a sensor network. ATSA works in three steps as following. Firstly, the root time node is selected, and then a hierarchical structure is established in the network, finally, by using time-agent, a pair wise synchronization is performed along the edges of this...
With the development and research of digital substation, some digital substations are built in power grid. Time synchronization in digital substation is researched, and some kinds of time synchronization system applied in substation are introduced. Application of time synchronization system based on SNTP in Guangdong power gird is put forward. This testing system based on SOE(sequence of events) resolution...
This paper presents the design and implementation of a power system sensor network (PSSN) for wide-area measurement. With the powerful data processing capability of sensor network, it is possible to build a real-time data network, that is more pervasive, more robust, more flexible, and more powerful in data processing, to overcome the shortcomings of current WAMS (wide-area measurement system). The...
The goal of our research is to develop a smart context-aware guide system that provides a smart and personalized guide services based on implicit awareness of context. As a context-aware guide application, we have been developing a location-aware smart bus guide system for Seoul. It will guide users to the nearby bus stops and provides users with information about the bus lines at the bus stops.
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