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The company QTPIE conducts research on drivers and their unconscious reactions when driving. To help, they use smart devices that today must be individually handled at the start and end of a run, and have individually set timestamps, which can lead to differences between the units when data is entered and collation of the units' data after a run. The purpose of this study is an integrated control system in the form of an Android mobile application that partly facilitates the start and end of a run, and partly synchronizes time stamps between all devices. The intention is to build a heterogeneous mobile network with a central control unit and implement time synchronization and investigate whether the heterogeneity affects the implementation of the network. The result was an Android mobile application that controlled selected external smart devices, synchronized these, and had time synchronization built in at the start of each run., Företaget QTPIE gör undersökningar på förare och deras omedvetna reaktioner vid körning. Till hjälp använder de smarta enheter som idag måste hanteras individuellt vid start och slut av en körning, samt har individuellt satta tidsstämplar, vilket kan leda till differenser mellan enheterna vid datainmatning och sammanstrålning av enheternas data efter en körning. Avsikten med den här studien är ett integrerat styrsystem i form av en Android mobilapplikation som dels underlättar vid start och slut av en körning, dels synkroniserar tidsstämplar mellan alla enheter. Avsikten är att bygga upp ett heterogent mobilt nätverk med en central kontrollenhet samt implementera tidssynkronisering och undersöka om heterogeniteten påverkar implementeringen av nätverket. Resultatet blev en Android mobilapplikation som styrde valda externa smarta enheter, synkroniserade dessa samt hade tidssynkronisering inbyggt vid start av varje körning.

The company QTPIE conducts research on drivers and their unconscious reactions when driving. To help, they use smart devices that today must be individually handled at the start and end of a run, and have individually set timestamps, which can lead to differences between the units when data is entered and collation of the units' data after a run. The purpose of this study is an integrated control system in the form of an Android mobile application that partly facilitates the start and end of a run, and partly synchronizes time stamps between all devices. The intention is to build a heterogeneous mobile network with a central control unit and implement time synchronization and investigate whether the heterogeneity affects the implementation of the network. The result was an Android mobile application that controlled selected external smart devices, synchronized these, and had time synchronization built in at the start of each run., Företaget QTPIE gör undersökningar på förare och deras omedvetna reaktioner vid körning. Till hjälp använder de smarta enheter som idag måste hanteras individuellt vid start och slut av en körning, samt har individuellt satta tidsstämplar, vilket kan leda till differenser mellan enheterna vid datainmatning och sammanstrålning av enheternas data efter en körning. Avsikten med den här studien är ett integrerat styrsystem i form av en Android mobilapplikation som dels underlättar vid start och slut av en körning, dels synkroniserar tidsstämplar mellan alla enheter. Avsikten är att bygga upp ett heterogent mobilt nätverk med en central kontrollenhet samt implementera tidssynkronisering och undersöka om heterogeniteten påverkar implementeringen av nätverket. Resultatet blev en Android mobilapplikation som styrde valda externa smarta enheter, synkroniserade dessa samt hade tidssynkronisering inbyggt vid start av varje körning.

Studien syftar till att analysera mätningar av tidsfördröjningar i inbyggda system som använder externa Wi-Fi-moduler och Network Time Protocol (NTP) för tidssynkronisering. Mätning i detta sammanhang innebär att man tar mätbara data som kan representera tidsfördröjningarna i numerisk form, vilket gör det möjligt att analysera och jämföra dem på ett objektivt sätt. Genom en grundlig litteraturstudie identifierades de olika elementen involverade i tidssynkroniseringsprocessen, inklusive egenskaper hos Wi-Fi-moduler, NTP-protokollet och andra systemkomponenter. Insamlad data analyserades för att upptäcka mönster och tendenser i tidsfördröjning. Det övergripande målet med studien var att bidra med specifika insikter som kan förbättra konfigurationen och prestandan hos inbyggda system. Genom att jämföra prestanda hos olika dataenheter och visa på variationer i tidsfördröjning, har studien gett konkreta mätdata i form av tid, dess genomsnitt och standardavvikelse. Dessa insikter kan användas för att designa mer tillförlitliga inbyggda system med förbättrad tidssynkronisering, vilket är avgörande för mcu som kräver hög precision och stabilitet., The study aims to analyze the measurements of time delays in embedded systems that use external Wi-Fi modules and the Network Time Protocol (NTP) for time synchronization. Measurement in this context means taking measurable data that can represent time delays in numerical form, making it possible to analyze and compare them objectively. Through a thorough literature review, the various elements involved in the time synchronization process were identified, including the characteristics of Wi-Fi modules, the NTP protocol, and other system components. Collected data were analyzed to detect patterns and trends in time delays. The overall goal of the study was to contribute specific insights that can improve the configuration and performance of embedded systems. By comparing the performance of different data units and showing variations in time delays, the study provided concrete guidelines and recommendations for engineers and developers. These insights can be used to design more reliable embedded systems with improved time synchronization, which is crucial for mcu requiring high precision and stability.

Studien syftar till att analysera mätningar av tidsfördröjningar i inbyggda system som använder externa Wi-Fi-moduler och Network Time Protocol (NTP) för tidssynkronisering. Mätning i detta sammanhang innebär att man tar mätbara data som kan representera tidsfördröjningarna i numerisk form, vilket gör det möjligt att analysera och jämföra dem på ett objektivt sätt. Genom en grundlig litteraturstudie identifierades de olika elementen involverade i tidssynkroniseringsprocessen, inklusive egenskaper hos Wi-Fi-moduler, NTP-protokollet och andra systemkomponenter. Insamlad data analyserades för att upptäcka mönster och tendenser i tidsfördröjning. Det övergripande målet med studien var att bidra med specifika insikter som kan förbättra konfigurationen och prestandan hos inbyggda system. Genom att jämföra prestanda hos olika dataenheter och visa på variationer i tidsfördröjning, har studien gett konkreta mätdata i form av tid, dess genomsnitt och standardavvikelse. Dessa insikter kan användas för att designa mer tillförlitliga inbyggda system med förbättrad tidssynkronisering, vilket är avgörande för mcu som kräver hög precision och stabilitet., The study aims to analyze the measurements of time delays in embedded systems that use external Wi-Fi modules and the Network Time Protocol (NTP) for time synchronization. Measurement in this context means taking measurable data that can represent time delays in numerical form, making it possible to analyze and compare them objectively. Through a thorough literature review, the various elements involved in the time synchronization process were identified, including the characteristics of Wi-Fi modules, the NTP protocol, and other system components. Collected data were analyzed to detect patterns and trends in time delays. The overall goal of the study was to contribute specific insights that can improve the configuration and performance of embedded systems. By comparing the performance of different data units and showing variations in time delays, the study provided concrete guidelines and recommendations for engineers and developers. These insights can be used to design more reliable embedded systems with improved time synchronization, which is crucial for mcu requiring high precision and stability.

Advancements in the Industrial Internet of Things (IIoT) and cyber-physical systems have driven the development of Industry 4.0, which has led to the emergence of advanced cloud-based applications. The web applications connect the field IIoT devices to 'the Internet'. The adequate performance of web applications depends on how seamlessly devices communicate and synchronize. The IIoT devices prominently use Message Queueing Telemetry Transport (MQTT) for machine to machine (M2M) communication. MQTT implements publish-subscribe-based broker architecture that distributes a common timebase to client devices. Such one-way time transfer methods are less accurate and often introduce synchronization errors. While existing time synchronization methods for field IIoT end devices, e.g., Simple Network Time Protocol (SNTP), provide adequate synchronization based on two-way delay transfer methods, their performance degrades significantly with deteriorating network conditions. To address these synchronization challenges, we propose SMQTT, a scalable, software-based, lightweight clock synchronization method for IIoT end devices utilizing MQTT-based M2M communication. The proposed method effectively leverages the broker architecture to implement a two-way delay-based synchronization algorithm. We conducted measurements in network deployments to evaluate the performance of the proposed algorithm. The results demonstrate that SMQTT surpasses both SNTP and state-of-the-art methods in terms of accuracy. Specifically, in our measurements under poor network conditions, SMQTT achieves synchronization performance improvements of 94% and 73% compared to SNTP and the state-of-the-art method, respectively.

The requirements of distributed systems implemented using IoT paradigms include the sharing of a common time reference. When the applications are intended for industrial scenarios, the desired time synchronization uncertainty decreases, due to the real-time needs of this kind of systems. Currently, the most diffused way to obtain a time reference for an Internet connected device is to use NTP (Network Time Protocol) for querying time servers. This paper is focused on industrial IoT applications and it is aimed to evaluate the impact that NTP synchronization performance and NTP throughput may have on the real-time host network. Analytical formulas for estimating the NTP impact are introduced. The work is complemented by the presentation of a use case that shows the use of NTP for the synchronization of a large industrial plant at field level. The results highlight the threat to the real-time behavior of the automation system caused by the uncontrolled peaks of traffic due to NTP. Last, some design considerations for mitigation of the impact are discussed. © 2020 IEEE.

This paper presents the complete design and implementation of a low-cost, low-footprint, network time protocol server core for field programmable gate arrays. The core uses a carefully designed modular architecture, which is fully implemented in hardware using digital circuits and systems. Most remarkable novelties introduced are a hardware-optimized timekeeping algorithm implementation, and a full-hardware protocol stack and automatic network configuration. As a result, the core is able to achieve similar accuracy and performance to typical high-performance network time protocol server equipment. The core uses a standard global positioning system receiver as time reference, has a small footprint and can easily fit in a low-range field-programmable chip, greatly scaling down from previous system-on-chip time synchronization systems. Accuracy and performance results show that the core can serve hundreds of thousands of network time clients with negligible accuracy degradation, in contrast to state-of-the-art high-performance time server equipment. Therefore, this core provides a valuable time server solution for a wide range of emerging embedded and distributed network applications such as the Internet of Things and the smart grid, at a fraction of the cost and footprint of current discrete and embedded solutions.

Este proyecto desarrolla un módulo de expansión para la plataforma RELY-CPPS de RELYUM que integre el hardware necesario para convertir al sistema en un reloj maestro. Para ello es necesario que el dispositivo RELY-CPPS sea capaz de integrar un servidor NTP/PTP que permi-ta sincronizar un número de clientes esclavos conectados a la red. Mientras que el servidor se implementa en la propia plataforma, todo el hardware necesario para dar soporte a la aplica-ción le corresponde a la unidad de expansión. Por tanto, el módulo se basa en un receptor de GPS que se conecta a la red de satélites de la cual obtiene la fecha y hora UTC y la señal PPS de manera muy precisa. Con ambas se puede sincronizar un sistema externo y son esenciales para crear el servidor NTP/PTP. A lo largo de este documento se detalla todo el proceso de desarrollo que lleva al diseño de una tarjeta de circuito impreso que proporcione el hardware necesario para llevar a cabo la aplicación de sincronización., Proiektu honek RELYUM-aren RELY-CPPS plataformarako hedapen-modulua garatzen du. Moduluak lehen aipatutako sistema maisu-erlojua bihurtzeko beharrezko hardwarea integra-tuko du. Horretarako, RELY-CPPS gailua NTP/PTP zerbitzari bat integratzeko gai izatea, sarean konektatutako bezero esklabo kopuru bat sinkronizatzera baimenduz, beharrezkoa izango da. Zerbitzaria bereko plataforman inplementatzen den ahala aplikazioari laguntza edo sos-tengu ematen den beharreko hardwarea hedapen-unitatera dagokio. Beraz, modulua satelite sarean konektatzen den GPS hartzaile batean oinarritzen da eta sare horretatik UTC data eta ordua eta PPS seinalea oso era zehatzean lortu ditzake. PPS eta UTC seinale biekin kanpo-sistema sinkroniza daiteke eta, gainera, NTP/PTP zerbitzaria sortzeko funtsezkoak dira. Dokumentu honetan inpreso-zirkuitu txartel baten diseinura eramaten duen garapen proze-su guztia eta sinkronizazio-aplikazioa burutzeko beharko den hardwarea zehazten da., This project develops an expansion module for the RELY-CPPS platform which implements the hardware needed to transform it into a master clock. In order to become a master clock, the RELY-CPPS device must have an NTP/PTP server that allows several slave clients in the network to be synchronized. While the server is developed in the platform’s system, the expansion unit must take care of all the hardware that supports the application. Therefore, the hardware is based on a GPS receiver connected to a satellite network from which obtains a highly accurate UTC date and time and PPS signal. An external system can be synchronized using both and they are essential for the development on the NTP/PTP server. Throughout this document, the entire process that leads to the design of a Printed Circuit Board whose purpose is to provide the essential hardware to carry out the synchronization application is detailed.

Este proyecto desarrolla un módulo de expansión para la plataforma RELY-CPPS de RELYUM que integre el hardware necesario para convertir al sistema en un reloj maestro. Para ello es necesario que el dispositivo RELY-CPPS sea capaz de integrar un servidor NTP/PTP que permi-ta sincronizar un número de clientes esclavos conectados a la red. Mientras que el servidor se implementa en la propia plataforma, todo el hardware necesario para dar soporte a la aplica-ción le corresponde a la unidad de expansión. Por tanto, el módulo se basa en un receptor de GPS que se conecta a la red de satélites de la cual obtiene la fecha y hora UTC y la señal PPS de manera muy precisa. Con ambas se puede sincronizar un sistema externo y son esenciales para crear el servidor NTP/PTP. A lo largo de este documento se detalla todo el proceso de desarrollo que lleva al diseño de una tarjeta de circuito impreso que proporcione el hardware necesario para llevar a cabo la aplicación de sincronización., Proiektu honek RELYUM-aren RELY-CPPS plataformarako hedapen-modulua garatzen du. Moduluak lehen aipatutako sistema maisu-erlojua bihurtzeko beharrezko hardwarea integra-tuko du. Horretarako, RELY-CPPS gailua NTP/PTP zerbitzari bat integratzeko gai izatea, sarean konektatutako bezero esklabo kopuru bat sinkronizatzera baimenduz, beharrezkoa izango da. Zerbitzaria bereko plataforman inplementatzen den ahala aplikazioari laguntza edo sos-tengu ematen den beharreko hardwarea hedapen-unitatera dagokio. Beraz, modulua satelite sarean konektatzen den GPS hartzaile batean oinarritzen da eta sare horretatik UTC data eta ordua eta PPS seinalea oso era zehatzean lortu ditzake. PPS eta UTC seinale biekin kanpo-sistema sinkroniza daiteke eta, gainera, NTP/PTP zerbitzaria sortzeko funtsezkoak dira. Dokumentu honetan inpreso-zirkuitu txartel baten diseinura eramaten duen garapen proze-su guztia eta sinkronizazio-aplikazioa burutzeko beharko den hardwarea zehazten da., This project develops an expansion module for the RELY-CPPS platform which implements the hardware needed to transform it into a master clock. In order to become a master clock, the RELY-CPPS device must have an NTP/PTP server that allows several slave clients in the network to be synchronized. While the server is developed in the platform’s system, the expansion unit must take care of all the hardware that supports the application. Therefore, the hardware is based on a GPS receiver connected to a satellite network from which obtains a highly accurate UTC date and time and PPS signal. An external system can be synchronized using both and they are essential for the development on the NTP/PTP server. Throughout this document, the entire process that leads to the design of a Printed Circuit Board whose purpose is to provide the essential hardware to carry out the synchronization application is detailed.

Este proyecto desarrolla un módulo de expansión para la plataforma RELY-CPPS de RELYUM que integre el hardware necesario para convertir al sistema en un reloj maestro. Para ello es necesario que el dispositivo RELY-CPPS sea capaz de integrar un servidor NTP/PTP que permi-ta sincronizar un número de clientes esclavos conectados a la red. Mientras que el servidor se implementa en la propia plataforma, todo el hardware necesario para dar soporte a la aplica-ción le corresponde a la unidad de expansión. Por tanto, el módulo se basa en un receptor de GPS que se conecta a la red de satélites de la cual obtiene la fecha y hora UTC y la señal PPS de manera muy precisa. Con ambas se puede sincronizar un sistema externo y son esenciales para crear el servidor NTP/PTP. A lo largo de este documento se detalla todo el proceso de desarrollo que lleva al diseño de una tarjeta de circuito impreso que proporcione el hardware necesario para llevar a cabo la aplicación de sincronización., Proiektu honek RELYUM-aren RELY-CPPS plataformarako hedapen-modulua garatzen du. Moduluak lehen aipatutako sistema maisu-erlojua bihurtzeko beharrezko hardwarea integra-tuko du. Horretarako, RELY-CPPS gailua NTP/PTP zerbitzari bat integratzeko gai izatea, sarean konektatutako bezero esklabo kopuru bat sinkronizatzera baimenduz, beharrezkoa izango da. Zerbitzaria bereko plataforman inplementatzen den ahala aplikazioari laguntza edo sos-tengu ematen den beharreko hardwarea hedapen-unitatera dagokio. Beraz, modulua satelite sarean konektatzen den GPS hartzaile batean oinarritzen da eta sare horretatik UTC data eta ordua eta PPS seinalea oso era zehatzean lortu ditzake. PPS eta UTC seinale biekin kanpo-sistema sinkroniza daiteke eta, gainera, NTP/PTP zerbitzaria sortzeko funtsezkoak dira. Dokumentu honetan inpreso-zirkuitu txartel baten diseinura eramaten duen garapen proze-su guztia eta sinkronizazio-aplikazioa burutzeko beharko den hardwarea zehazten da., This project develops an expansion module for the RELY-CPPS platform which implements the hardware needed to transform it into a master clock. In order to become a master clock, the RELY-CPPS device must have an NTP/PTP server that allows several slave clients in the network to be synchronized. While the server is developed in the platform’s system, the expansion unit must take care of all the hardware that supports the application. Therefore, the hardware is based on a GPS receiver connected to a satellite network from which obtains a highly accurate UTC date and time and PPS signal. An external system can be synchronized using both and they are essential for the development on the NTP/PTP server. Throughout this document, the entire process that leads to the design of a Printed Circuit Board whose purpose is to provide the essential hardware to carry out the synchronization application is detailed.

Tato bakalářská práce popisuje technologie a způsoby pro synchronizaci systémového času v počítačích a serverech pomocí protokolů pro časovou synchronizaci. Teoretická část popisuje časovou problematiku, nutnost přesného času, práce NTP a SNTP protokolu. Dále se bude praktická část zabývat přesností času v počítači bez automatické synchronizace času., This document describes technologies and ways to synchronize local system time in computers or servers using synchronization time protocol. Theoretical part describes time problems, the need for accurate time, network time protocol and simple network time protocol. Practical part is going to examine time accuracy in computer witout automatic time synchronization., Fakulta elektrotechniky a informatiky, Cílem bakalářské práce bylo zjistit, jakými způsoby lze synchronizovat systémový čas počítače časem UTC na počítačích s operačními systémy Linux a Windows a ověřit synchronizaci na praktickém příkladu. Dle vedoucího byly cíle práce splněny v plném rozsahu. Práce může sloužit jako návod jak přistoupit k synchronizaci systémového času počítače. V bakalářské práci se vyskytlo několik nepřesností. Obhajoba bakalářské práce odpovídá klasifikačnímu stupni velmi dobře.

Tato bakalářská práce popisuje technologie a způsoby pro synchronizaci systémového času v počítačích a serverech pomocí protokolů pro časovou synchronizaci. Teoretická část popisuje časovou problematiku, nutnost přesného času, práce NTP a SNTP protokolu. Dále se bude praktická část zabývat přesností času v počítači bez automatické synchronizace času., This document describes technologies and ways to synchronize local system time in computers or servers using synchronization time protocol. Theoretical part describes time problems, the need for accurate time, network time protocol and simple network time protocol. Practical part is going to examine time accuracy in computer witout automatic time synchronization., Fakulta elektrotechniky a informatiky, Cílem bakalářské práce bylo zjistit, jakými způsoby lze synchronizovat systémový čas počítače časem UTC na počítačích s operačními systémy Linux a Windows a ověřit synchronizaci na praktickém příkladu. Dle vedoucího byly cíle práce splněny v plném rozsahu. Práce může sloužit jako návod jak přistoupit k synchronizaci systémového času počítače. V bakalářské práci se vyskytlo několik nepřesností. Obhajoba bakalářské práce odpovídá klasifikačnímu stupni velmi dobře.

The ever-increasing demand for high quality services require a good quantification of performance parameters such as delay and jitter. Let’s consider one of the parameters, jitter, which is the difference between the inter arrival time of two subsequent packets and the average inter-arrival time. The arrival or departure time of a packet is termed as time-stamp. The accuracy of the timestamp will influence any performance metrics based on the arrival/departure time of a packet. Hence, the knowledge or awareness of time-stamping accuracy is important for performance evaluation. This study investigates how the time-stamping process is affected by virtualization, +46723219830

The ever-increasing demand for high quality services require a good quantification of performance parameters such as delay and jitter. Let’s consider one of the parameters, jitter, which is the difference between the inter arrival time of two subsequent packets and the average inter-arrival time. The arrival or departure time of a packet is termed as time-stamp. The accuracy of the timestamp will influence any performance metrics based on the arrival/departure time of a packet. Hence, the knowledge or awareness of time-stamping accuracy is important for performance evaluation. This study investigates how the time-stamping process is affected by virtualization, +46723219830

The ever-increasing demand for high quality services require a good quantification of performance parameters such as delay and jitter. Let’s consider one of the parameters, jitter, which is the difference between the inter arrival time of two subsequent packets and the average inter-arrival time. The arrival or departure time of a packet is termed as time-stamp. The accuracy of the timestamp will influence any performance metrics based on the arrival/departure time of a packet. Hence, the knowledge or awareness of time-stamping accuracy is important for performance evaluation. This study investigates how the time-stamping process is affected by virtualization, +46723219830

The ever-increasing demand for high quality services require a good quantification of performance parameters such as delay and jitter. Let’s consider one of the parameters, jitter, which is the difference between the inter arrival time of two subsequent packets and the average inter-arrival time. The arrival or departure time of a packet is termed as time-stamp. The accuracy of the timestamp will influence any performance metrics based on the arrival/departure time of a packet. Hence, the knowledge or awareness of time-stamping accuracy is important for performance evaluation. This study investigates how the time-stamping process is affected by virtualization, +46723219830

The ever-increasing demand for high quality services require a good quantification of performance parameters such as delay and jitter. Let’s consider one of the parameters, jitter, which is the difference between the inter arrival time of two subsequent packets and the average inter-arrival time. The arrival or departure time of a packet is termed as time-stamp. The accuracy of the timestamp will influence any performance metrics based on the arrival/departure time of a packet. Hence, the knowledge or awareness of time-stamping accuracy is important for performance evaluation. This study investigates how the time-stamping process is affected by virtualization, +46723219830

The ever-increasing demand for high quality services require a good quantification of performance parameters such as delay and jitter. Let’s consider one of the parameters, jitter, which is the difference between the inter arrival time of two subsequent packets and the average inter-arrival time. The arrival or departure time of a packet is termed as time-stamp. The accuracy of the timestamp will influence any performance metrics based on the arrival/departure time of a packet. Hence, the knowledge or awareness of time-stamping accuracy is important for performance evaluation. This study investigates how the time-stamping process is affected by virtualization, +46723219830

type:text, Among the standard time reporting systems, the Network Time Protocol (NTP) provides an easy and accurate way for the accessing the Universal time. The NTP is taking the benefit of the pervasiveness of the computer network during the recent information-oriented modern world. The NTP Pool Project is the project to provide a distributed framework of the NTP servers. As the ever-increasing amounts of the requests of the standard time, the number of the NTP servers provided by the NTP Pool Project will be extended correspondingly. This paper will provide the detailed introduction on the framework of the NTP Pool Project, the development of the NTP Pool Project in Taiwan at the present time, and the followed by the suggestions of the implementation of the NTP pool project.

Among the standard time reporting systems, the Network Time Protocol (NTP) provides an easy and accurate way for the accessing the Universal time. The NTP is taking the benefit of the pervasiveness of the computer network during the recent information-oriented modern world. The NTP Pool Project is the project to provide a distributed framework of the NTP servers. As the ever-increasing amounts of the requests of the standard time, the number of the NTP servers provided by the NTP Pool Project will be extended correspondingly. This paper will provide the detailed introduction on the framework of the NTP Pool Project, the development of the NTP Pool Project in Taiwan at the present time, and the followed by the suggestions of the implementation of the NTP pool project.

Among the standard time reporting systems, the Network Time Protocol (NTP) provides an easy and accurate way for the accessing the Universal time. The NTP is taking the benefit of the pervasiveness of the computer network during the recent information-oriented modern world. The NTP Pool Project is the project to provide a distributed framework of the NTP servers. As the ever-increasing amounts of the requests of the standard time, the number of the NTP servers provided by the NTP Pool Project will be extended correspondingly. This paper will provide the detailed introduction on the framework of the NTP Pool Project, the development of the NTP Pool Project in Taiwan at the present time, and the followed by the suggestions of the implementation of the NTP pool project.

In this article, an Internet-based remote control system is designed and implemented. The communication is based on the Master-Slave structure. The Master PC communicates with the Slave from about 40km away by UDP protocol. In order to guarantee the Master and Slave clocks to be synchronized, the NTP (Network Time Protocol) is used in both sides. The packets are sent together with time-stamps. The controller design (master) relies on a remote observer that achieves a state prediction of the application (slave), despite the variable communication delays. The Slave comprises a PC and a robot Miabot of Merlin company. The protocol Bluetooth is used between the local PC and the robot. Internet-based remote systems are subject to variable time delays (including communication and data-sampling delays) and data packets losses (due to the unstable Internet network). We have continuously tested the RTT (round-trip-time) between the two PCs in the daytime and nighttime by the protocol ICMP (Internet Control Message). From these tests, an evaluation of the maximal time delay is obtained. Our structure allows one to guarantee an exponential stabilization performance, which is proven via a Lyapunov-Krassovski functional technique and involves the estimated delay upperbound. This means that the guaranteed decay rate is computed (via some LMI optimization) in relation to some maximal value of the communication delays. Of course, for greater delay values, the performance cannot be guaranteed anymore and an alternative solution has to be considered. In our system, we give a command for the robot to stop until the communication comes back to a sufficient quality., QC 20141020

This paper describes a massive survey of Network Time Protocol (NTP) servers and clients in order to discover statistics of time and frequency errors, as well as determine the health and welfare of the NTP synchronization subnet operating in the global Internet. Among the conclusions of the survey are that most NTP clocks are within 21 ms of their synchronization sources and all are within 29 ms on average. However, additional errors up to one-half the roundtrip delay are possible, but relatively rare. There is, however, a disturbing incidence of improperly operating sewers and misguided server configurations., See also ADA418244. Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting(29th), held in Long Beach, CA, on 2-4 Dec 1997. Sponsored in part by NSF grant no. NCR93-01002.

Tato práce se zabývá návrhem bezdrátové časomíry pro disciplíny požárního sportu. Cílem je nahradit dlouhé kabelové rozvody bezdrátovými spoji při zachování srovnatelné, nebo lepší spolehlivosti. S tím souvisí potřeba synchronizovat hodiny mezi jednotlivými bezdrátovými moduly. Důležitou částí práce je proto návrh a implementace vhodného synchronizačního algoritmu a komunikačního protokolu. Navržený systém byl realizován formou prototypu na vývojové platformě Texas Instruments LaunchPad EXP430FR4133 s využitím bezdrátových modulů s čipem Texas Instruments CC1101. Parametry navrženého systému časomíry (zejména přesnost synchronizace a měření) byly ověřeny v laboratorních podmínkách., This work describes the design of wireless timer for fire sport disciplines. Its aim is to replace long wires with wireless communication while preserving equal or better reliability. Important part is the need for clock synchronization between wireless modules. Related topic is selection of suitable synchronization algorithm and communication protocol. The proposed system was realized in form of prototype using Texas Instruments's development platform LaunchPad EXP 430 FR4133 and wireless modules with Texas Instruments's chip CC1101. Parameters of designed system (especially the accuracy of time synchronization and measurement) were verified in laboratory.

Tato práce se zabývá návrhem bezdrátové časomíry pro disciplíny požárního sportu. Cílem je nahradit dlouhé kabelové rozvody bezdrátovými spoji při zachování srovnatelné, nebo lepší spolehlivosti. S tím souvisí potřeba synchronizovat hodiny mezi jednotlivými bezdrátovými moduly. Důležitou částí práce je proto návrh a implementace vhodného synchronizačního algoritmu a komunikačního protokolu. Navržený systém byl realizován formou prototypu na vývojové platformě Texas Instruments LaunchPad EXP430FR4133 s využitím bezdrátových modulů s čipem Texas Instruments CC1101. Parametry navrženého systému časomíry (zejména přesnost synchronizace a měření) byly ověřeny v laboratorních podmínkách., This work describes the design of wireless timer for fire sport disciplines. Its aim is to replace long wires with wireless communication while preserving equal or better reliability. Important part is the need for clock synchronization between wireless modules. Related topic is selection of suitable synchronization algorithm and communication protocol. The proposed system was realized in form of prototype using Texas Instruments's development platform LaunchPad EXP 430 FR4133 and wireless modules with Texas Instruments's chip CC1101. Parameters of designed system (especially the accuracy of time synchronization and measurement) were verified in laboratory.

Tato práce se zabývá návrhem bezdrátové časomíry pro disciplíny požárního sportu. Cílem je nahradit dlouhé kabelové rozvody bezdrátovými spoji při zachování srovnatelné, nebo lepší spolehlivosti. S tím souvisí potřeba synchronizovat hodiny mezi jednotlivými bezdrátovými moduly. Důležitou částí práce je proto návrh a implementace vhodného synchronizačního algoritmu a komunikačního protokolu. Navržený systém byl realizován formou prototypu na vývojové platformě Texas Instruments LaunchPad EXP430FR4133 s využitím bezdrátových modulů s čipem Texas Instruments CC1101. Parametry navrženého systému časomíry (zejména přesnost synchronizace a měření) byly ověřeny v laboratorních podmínkách., This work describes the design of wireless timer for fire sport disciplines. Its aim is to replace long wires with wireless communication while preserving equal or better reliability. Important part is the need for clock synchronization between wireless modules. Related topic is selection of suitable synchronization algorithm and communication protocol. The proposed system was realized in form of prototype using Texas Instruments's development platform LaunchPad EXP 430 FR4133 and wireless modules with Texas Instruments's chip CC1101. Parameters of designed system (especially the accuracy of time synchronization and measurement) were verified in laboratory.

Among the standard time reporting systems, the Network Time Protocol (NTP) provides an easy and accurate way for the accessing the Universal time. The NTP is taking the benefit of the pervasiveness of the computer network during the recent information-oriented modern world. The NTP Pool Project is the project to provide a distributed framework of the NTP servers. As the ever-increasing amounts of the requests of the standard time, the number of the NTP servers provided by the NTP Pool Project will be extended correspondingly. This paper will provide the detailed introduction on the framework of the NTP Pool Project, the development of the NTP Pool Project in Taiwan at the present time, and the followed by the suggestions of the implementation of the NTP pool project.

Tato bakalářská práce se zabývá analýzou a implementací serverových služeb DNS, DHCP a NTP do zátěžového testeru vyvíjeného na Ústavu telekomunikací. Všechny služby jsou realizovány v Linuxové distribuci Ubuntu, přes programové balíčky bind9, isc-dhcp-server a ntp. Všem službám bylo vytvořeno grafické rozhraní, pomocí kterého je možné služby spustit a vypnout. Dále je možné definovat IP adresu verze 4 i 6, port a síťové rozhraní, na kterém daná služba naslouchá. Všechny služby pro svůj provoz využívají nově vytvořené konfigurační soubory pomocí modulu Server Emulator, přičemž původní konfigurace zůstává nedotčena. V práci je popsán teoretický základ vybraných serverových služeb a následně je popsána samotná implementace do prostředí zátěžového testeru do modulu Server Emulator., This bachelor thesis deals with the analysis and implementation of DNS, DHCP and NTP server services into a stress tester developed at the Institute of Telecommunications. All services are implemented in the Ubuntu Linux distribution through the software packages bind9, isc-dhcp-server and ntp. A graphical interface has been created for all services that can be used to start and stop the services. It is also possible to define the version 4 and 6 IP address, port and network interface on which the service listens. All services use the newly created configuration files for their operation using the Server Emulator module, while the original configuration is retained. This article describes the theoretical basis of the selected server services and then the

Tato bakalářská práce se zabývá analýzou a implementací serverových služeb DNS, DHCP a NTP do zátěžového testeru vyvíjeného na Ústavu telekomunikací. Všechny služby jsou realizovány v Linuxové distribuci Ubuntu, přes programové balíčky bind9, isc-dhcp-server a ntp. Všem službám bylo vytvořeno grafické rozhraní, pomocí kterého je možné služby spustit a vypnout. Dále je možné definovat IP adresu verze 4 i 6, port a síťové rozhraní, na kterém daná služba naslouchá. Všechny služby pro svůj provoz využívají nově vytvořené konfigurační soubory pomocí modulu Server Emulator, přičemž původní konfigurace zůstává nedotčena. V práci je popsán teoretický základ vybraných serverových služeb a následně je popsána samotná implementace do prostředí zátěžového testeru do modulu Server Emulator., This bachelor thesis deals with the analysis and implementation of DNS, DHCP and NTP server services into a stress tester developed at the Institute of Telecommunications. All services are implemented in the Ubuntu Linux distribution through the software packages bind9, isc-dhcp-server and ntp. A graphical interface has been created for all services that can be used to start and stop the services. It is also possible to define the version 4 and 6 IP address, port and network interface on which the service listens. All services use the newly created configuration files for their operation using the Server Emulator module, while the original configuration is retained. This article describes the theoretical basis of the selected server services and then the

Tato bakalářská práce se zabývá analýzou a implementací serverových služeb DNS, DHCP a NTP do zátěžového testeru vyvíjeného na Ústavu telekomunikací. Všechny služby jsou realizovány v Linuxové distribuci Ubuntu, přes programové balíčky bind9, isc-dhcp-server a ntp. Všem službám bylo vytvořeno grafické rozhraní, pomocí kterého je možné služby spustit a vypnout. Dále je možné definovat IP adresu verze 4 i 6, port a síťové rozhraní, na kterém daná služba naslouchá. Všechny služby pro svůj provoz využívají nově vytvořené konfigurační soubory pomocí modulu Server Emulator, přičemž původní konfigurace zůstává nedotčena. V práci je popsán teoretický základ vybraných serverových služeb a následně je popsána samotná implementace do prostředí zátěžového testeru do modulu Server Emulator., This bachelor thesis deals with the analysis and implementation of DNS, DHCP and NTP server services into a stress tester developed at the Institute of Telecommunications. All services are implemented in the Ubuntu Linux distribution through the software packages bind9, isc-dhcp-server and ntp. A graphical interface has been created for all services that can be used to start and stop the services. It is also possible to define the version 4 and 6 IP address, port and network interface on which the service listens. All services use the newly created configuration files for their operation using the Server Emulator module, while the original configuration is retained. This article describes the theoretical basis of the selected server services and then the

Tato práce se zabývá návrhem bezdrátové časomíry pro disciplíny požárního sportu. Cílem je nahradit dlouhé kabelové rozvody bezdrátovými spoji při zachování srovnatelné, nebo lepší spolehlivosti. S tím souvisí potřeba synchronizovat hodiny mezi jednotlivými bezdrátovými moduly. Důležitou částí práce je proto návrh a implementace vhodného synchronizačního algoritmu a komunikačního protokolu. Navržený systém byl realizován formou prototypu na vývojové platformě Texas Instruments LaunchPad EXP430FR4133 s využitím bezdrátových modulů s čipem Texas Instruments CC1101. Parametry navrženého systému časomíry (zejména přesnost synchronizace a měření) byly ověřeny v laboratorních podmínkách., This work describes the design of wireless timer for fire sport disciplines. Its aim is to replace long wires with wireless communication while preserving equal or better reliability. Important part is the need for clock synchronization between wireless modules. Related topic is selection of suitable synchronization algorithm and communication protocol. The proposed system was realized in form of prototype using Texas Instruments's development platform LaunchPad EXP 430 FR4133 and wireless modules with Texas Instruments's chip CC1101. Parameters of designed system (especially the accuracy of time synchronization and measurement) were verified in laboratory.

Tato práce se zabývá návrhem bezdrátové časomíry pro disciplíny požárního sportu. Cílem je nahradit dlouhé kabelové rozvody bezdrátovými spoji při zachování srovnatelné, nebo lepší spolehlivosti. S tím souvisí potřeba synchronizovat hodiny mezi jednotlivými bezdrátovými moduly. Důležitou částí práce je proto návrh a implementace vhodného synchronizačního algoritmu a komunikačního protokolu. Navržený systém byl realizován formou prototypu na vývojové platformě Texas Instruments LaunchPad EXP430FR4133 s využitím bezdrátových modulů s čipem Texas Instruments CC1101. Parametry navrženého systému časomíry (zejména přesnost synchronizace a měření) byly ověřeny v laboratorních podmínkách., This work describes the design of wireless timer for fire sport disciplines. Its aim is to replace long wires with wireless communication while preserving equal or better reliability. Important part is the need for clock synchronization between wireless modules. Related topic is selection of suitable synchronization algorithm and communication protocol. The proposed system was realized in form of prototype using Texas Instruments's development platform LaunchPad EXP 430 FR4133 and wireless modules with Texas Instruments's chip CC1101. Parameters of designed system (especially the accuracy of time synchronization and measurement) were verified in laboratory.

Tato bakalářská práce se zabývá analýzou a implementací serverových služeb DNS, DHCP a NTP do zátěžového testeru vyvíjeného na Ústavu telekomunikací. Všechny služby jsou realizovány v Linuxové distribuci Ubuntu, přes programové balíčky bind9, isc-dhcp-server a ntp. Všem službám bylo vytvořeno grafické rozhraní, pomocí kterého je možné služby spustit a vypnout. Dále je možné definovat IP adresu verze 4 i 6, port a síťové rozhraní, na kterém daná služba naslouchá. Všechny služby pro svůj provoz využívají nově vytvořené konfigurační soubory pomocí modulu Server Emulator, přičemž původní konfigurace zůstává nedotčena. V práci je popsán teoretický základ vybraných serverových služeb a následně je popsána samotná implementace do prostředí zátěžového testeru do modulu Server Emulator., This bachelor thesis deals with the analysis and implementation of DNS, DHCP and NTP server services into a stress tester developed at the Institute of Telecommunications. All services are implemented in the Ubuntu Linux distribution through the software packages bind9, isc-dhcp-server and ntp. A graphical interface has been created for all services that can be used to start and stop the services. It is also possible to define the version 4 and 6 IP address, port and network interface on which the service listens. All services use the newly created configuration files for their operation using the Server Emulator module, while the original configuration is retained. This article describes the theoretical basis of the selected server services and then the

Tato práce se zabývá návrhem bezdrátové časomíry pro disciplíny požárního sportu. Cílem je nahradit dlouhé kabelové rozvody bezdrátovými spoji při zachování srovnatelné, nebo lepší spolehlivosti. S tím souvisí potřeba synchronizovat hodiny mezi jednotlivými bezdrátovými moduly. Důležitou částí práce je proto návrh a implementace vhodného synchronizačního algoritmu a komunikačního protokolu. Navržený systém byl realizován formou prototypu na vývojové platformě Texas Instruments LaunchPad EXP430FR4133 s využitím bezdrátových modulů s čipem Texas Instruments CC1101. Parametry navrženého systému časomíry (zejména přesnost synchronizace a měření) byly ověřeny v laboratorních podmínkách., This work describes the design of wireless timer for fire sport disciplines. Its aim is to replace long wires with wireless communication while preserving equal or better reliability. Important part is the need for clock synchronization between wireless modules. Related topic is selection of suitable synchronization algorithm and communication protocol. The proposed system was realized in form of prototype using Texas Instruments's development platform LaunchPad EXP 430 FR4133 and wireless modules with Texas Instruments's chip CC1101. Parameters of designed system (especially the accuracy of time synchronization and measurement) were verified in laboratory.

Tato práce se zabývá návrhem bezdrátové časomíry pro disciplíny požárního sportu. Cílem je nahradit dlouhé kabelové rozvody bezdrátovými spoji při zachování srovnatelné, nebo lepší spolehlivosti. S tím souvisí potřeba synchronizovat hodiny mezi jednotlivými bezdrátovými moduly. Důležitou částí práce je proto návrh a implementace vhodného synchronizačního algoritmu a komunikačního protokolu. Navržený systém byl realizován formou prototypu na vývojové platformě Texas Instruments LaunchPad EXP430FR4133 s využitím bezdrátových modulů s čipem Texas Instruments CC1101. Parametry navrženého systému časomíry (zejména přesnost synchronizace a měření) byly ověřeny v laboratorních podmínkách., This work describes the design of wireless timer for fire sport disciplines. Its aim is to replace long wires with wireless communication while preserving equal or better reliability. Important part is the need for clock synchronization between wireless modules. Related topic is selection of suitable synchronization algorithm and communication protocol. The proposed system was realized in form of prototype using Texas Instruments's development platform LaunchPad EXP 430 FR4133 and wireless modules with Texas Instruments's chip CC1101. Parameters of designed system (especially the accuracy of time synchronization and measurement) were verified in laboratory.