Maximum time interval error

Abstract: This paper describes the long-term performance of White Rabbit (WR) based time and frequency transfer in the systems deployed at CERN and Gran Sasso National Laboratory. WR is a new technology based on IEEE 1588-2008 and Synchronous Ethernet which allows for sub-nanosecond accuracy and picosecond precision of synchronization in an Ethernet-based network. The first installation of WR is used in the CERN Neutrino to Gran Sasso (CNGS) project to transfer the Coordinated Universal Time (UTC) from a Global Positioning System (GPS) receiver to the underground extraction/detection points. The data collected during the system operation is used to evaluate its performance. Additionally, the performance in varying temperature conditions is verified with tests in a climatic chamber. We evaluate time transfer by measuring the offset between the time reference and the time receiver (WR Node). The stability of the transfered frequency is evaluated by analyzing the Allan Deviation (ADEV) and the Maximum Time Interval Error (MTIE).

Abstract: Maximum time-interval error (MTIE) is historically one of the main time-domain quantities considered for the specification of clock stability requirements in telecommunications standards. In this paper, MTIE is first introduced according to its formal definition. Then, the main issue of its experimental measurement is pointed out: the heavy computational effort in most cases of practical interest. Therefore, two suitable methods to face up to this issue are herein discussed, summarizing the state of the art of MTIE measurement techniques in telecommunications. A new effective technique is proposed, with the aim to provide an easy but accurate way to test the compliance of telecommunications clocks with MTIE standard masks. Several results, measuring clocks deployed in telecommunications networks, are provided.

Abstract: In this paper, the time effective calculation methods of the maximum time interval error estimate (MT/spl circ/IE) are proposed. The formula of the MTIE estimator and the time error sequence measurement conditions are presented. The method of MT/spl circ/IE calculation based directly on the estimator's definition is the first method presented. Then the methods which enable computation of the MTIE estimate in a rather short time are proposed. The experiment of MT/spl circ/IE calculation using the presented method is described. The comparison between the methods is made. The pros and cons of the proposed methods are pointed out.

Abstract: The maximum time interval error (MTIE) is historically one of the main time-domain quantities for the specification of clock stability requirements in telecommunications standards. Nevertheless, plain computation of the MTIE standard estimator proves cumbersome in most cases of practical interest, due to its heavy computational weight. In this paper, MTIE is first introduced according to its standard definition. Then, a fast algorithm based on binary decomposition to compute the MTIE standard estimator is described. The computational weight of the binary decomposition algorithm is compared to that of the estimator plain calculation, showing that the number of operations needed is reduced to a term proportional to Nlog/sub 2/N instead of N/sup 2/. A heavy computational saving is therefore achieved, thus making feasible MTIE evaluation based on even long sequences of time error (TE) samples. The algorithm proposed is finally applied to TE sequences generated by simulation of all the types of power-law noise, in order to check its effectiveness and correctness.