Long-distance clock distribution with PDV using NTP and PTP

Data collected in the Time-based Technologies and Networks Laboratory of the University of Granada when researching packet-based time synchronization over Wide-Area Networks.

This dataset includes results from the different experiments carried out with the ptp4l PTP client and chrony NTP client for time transfer over long distances, including our custom approach using offset estimation filters. All experiments are based on the case of time transfer between the Spanish UTC designated institute at the Real Instituto y Observatorio de la Armada (ROA) in San Fernando, Cádiz; and the University of Granada in Granada. Apart from the field tests, data from experiments using network emulation on a Calnex Paragon-X and stability data from the NIC used (an Intel XXV710-DA2T) are also included.

The dataset is divided as follows:

intel-xxv710da2t-phm-100k.csv contains the time error between a free-running Intel XXV710-DA2T and our common-view-disciplined passive hydrogen maser (PHM). Measurements where made using 1 PPS signals and a frequency counter, and are specified in seconds.

delay.tar contains delay measurements between UGR and ROA labs over the andalusian CICA network using the GNSS common-view technique for accurate time synchronization between the measuring nodes. The CSV files included in this TAR are in long format, containing three columns (timestamp, metric and value). The metrics included are:

owd_s2c (float64): One-way delay from ROA to UGR, in seconds.

owd_c2s (float64): One-way delay from UGR to ROA, in seconds.

chrony.tar contains experimental data from chrony NTP synchronization between ROA (server) and UGR (client). The CSV files included in this TAR are in long format, containing three columns (timestamp, metric and value). The metrics included are:

offset_hw  (float64): Time error observation between the server and client using a frequency counter and 1 PPS signals, in seconds.

Please note that, for the network emulation tests this comparison is made directly between the server and the client, using the client and the common-view-disciplined PHM for the field tests instead.

ptp4l.tar contains experimental data from ptp4l PTP synchronization between ROA (server) and UGR (client). These CSV files are also in long format (timestamp, metric and value). The metrics included are:

offset_hw  (float64): Time error observation between the server and client using a frequency counter and 1 PPS signals, in seconds.

offset_sw (float64): Time error estimation given by the ptp4l client and used as input for the clock servo, in seconds.

offset_raw (float64): Raw time error estimation given by the ptp4l client, in seconds.

delay_raw (float64): Raw one-way downwards delay estimation given by the ptp4l client, in seconds.

delay_filt (float64): Filtered one-way downwards delay estimation given by the ptp4l client, in seconds.

freq (float64): Frequency adjustment applied to the local oscillator by the ptp4l client.

Please note that, when using the offset filters, the offset_raw metric contains the raw estimations that are the input of the filter, while offset_sw is the filtered estimation produced as output of the filter. If no offset filter is used, offset_raw and offset_sw have the same value.

File names contain metadata about the actual experiment performed, and have the following structure: __-----