Precision Time Protocol

About: Precision Time Protocol is a research topic. Over the lifetime, 604 publications have been published within this topic receiving 6006 citations. The topic is also known as: PTP & IEEE 1588.

Clock Synchronization in IoT Network Using Cloud Computing

Abstract: The Internet of Things is a trending future technological revolution that emerging distributed computing and real-time based application and its development depends on dynamic technical innovation in a number of important fields from wireless sensors to nanotechnology. Cloud integration with IoT made things more convenient and easy. Clock synchronization between systems in a distributed network is the complex and tedious job. It is mandatory to get sync with other and source as well. There are many proposed ways of data synchronization protocols like NTP, global position system to maintain sync process between Systems or IoT devices network. In this paper, we are proposing a clock synchronization approach to sync clocks between IoTs and Cloud which are connected with each other in distributed network. Here we have used cloud service Software as a Service to collect the information to analysis and trigger the results action to IoTs. In this paper, we present the Clock Synchronization based on precision time protocol between IoTs simulation model for Omnet++ with INET framework, which allows us to check clock sync accuracy with a different network configured topologies. We have tried to minimize the clock drift with clock offset updating and with master–slave phenomena also minimize the master–slave delay. To show our simulation results we have used chunks nodes of IoTs in distributed manner placed in different places with different clock values. The simulation result shows that proposed approach works in the desired manner within ideal and network delay symmetry.

Synchronization status monitoring method based on time offset

Abstract: The invention relates to a synchronization status monitoring method based on time offset. The method comprises the following steps of: obtaining time offset data Offset computed by time synchronization cycles and offset data generation TOD (time of data) information by interfacing a 1588v2 time synchronization PTP (precision time protocol) module; carrying out computational analysis on the acquired Offset to obtain the synchronization status indication information of the corresponding data synchronization status; transferring the value of the Offset, the synchronization status indication information and the corresponding TOD information to an NMS (network management system) via an NMS interface; and the NMS storing the received data, carrying out corresponding image-based display and triggering corresponding alarm according to the data synchronization status indication. The method is characterized in that based on the 1588v2 time synchronization timestamp mechanism, the offset data computed by time synchronization is acquired by interfacing the time synchronization protocol layer to carry out computational analysis on the data and the network management server is reported to carry out long-term storage and image-based display of the data and trigger synchronization status abnormity alarm.

System and method for improving the timestamp precision in a precision time protocol (PTP) device

Abstract: In accordance with the present invention is provided a system and method for improving a timestamp precision in a precision timestamp protocol (PTP) device. The present invention provides for dynamic adjustment of otherwise uncertainty of the latency of a connection between two devices connected together through a gearbox and/or a block sync circuit. The dynamic adjustment is accomplished by identifying the alignment of data within the gearbox and block sync and adjusting the timestamp assigned to the data based upon the identified alignment to remove the jitter associated with the gearbox and the block sync, thereby improving the timestamp precision in the PTP device. In a particular embodiment, the invention is employed in a serial-deserializer (SERDES) device.

Performance bounds for phase offset estimation in IEEE 1588 synchronization

Abstract: There has been recent interest in the use of packet-based synchronization techniques based on the IEEE 1588 Precision Time Protocol, in order to meet challenges arising in mobile telecommunication networks. An important problem in this area is to design estimators that determine the phase offset of slave clocks, while being resilient to the degrading effects of random network traversal times. While a number of simple non-parametric estimation techniques for this problem have been described in literature, little is known about the best theoretically achievable accuracy. In this paper, we address this issue by describing two novel lower bounds on the error variance of estimators for such problems. These bounds are obtained by adapting two classical Bayesian estimation bounds, namely the Weiss-Weinstien bound and the Ziv-Zakai bound, to a non-Bayesian estimation scenario. The results provide new insights into scenarios where existing phase offset estimation techniques perform well, and where significant scope for performance improvements exists.

Airborne network switch with ieee-1588 support

Abstract: Today’s data acquisition systems are typically comprised of data collectors connected to multiplexers via serial, point-to-point links. Data flows upstream from the sensors or avionics buses to the data acquisition units, to the multiplexer and finally to the recorder or telemetry transmitter. In a networked data acquisition system, data is transported through the network “cloud”. At the core of the network “cloud” is the network switch. The switch is responsible for distributing and directing data within the network. Network switches are commonplace in the commercial realm. Many businesses today could not function without them. A network-based data acquisition system, however, places additional burdens on the network switch. As in a commercial network, the switch in a data acquisition system must be able to distribute data packets within the network. In addition, it must be able to perform in a harsh environment, occupy a minimal amount of space, operate with limited or no external cooling, be configurable, and deal with the distribution of time information. This paper describes the required features of a ruggedized network switch and the implementation challenges facing its design. As a core component of a network-based data acquisition system, an ideal switch must be capable of operating in a large number of configurations, transporting and aggregating data between data sources and data sinks, with a mixture of devices operating at rates ranging from a few thousand bits per second to several gigabits per second, over twisted pair or fiber optic links. To ensure time coherency, the switch must also facilitate a time distribution mechanism, e.g., IEEE-1588 Precision Time Protocol (PTP). The gigabit switch described here uses the PTP to implement an end-to-end clock synchronization, for distributed acquisition nodes, to within 300 nanoseconds.