The 10th WR workshop was held at CERN, Geneva (Switzerland) on 6-7
October 2018, with 56
Topics included WR technology evolution, applications and the process of
standardisation under IEEE 1588.
There was also an introduction for newcomers and ample time for informal
discussion in between sessions and during the workshop dinner.
Introduction to WR: an easy introduction to the technology,
status, plans and a survey of its current users, mainly aimed at
newcomers. We will also briefly discuss the basic delay calibration
procedure for switches and nodes, in view of placing Peter's later
discussion on absolute calibration in context.
WR switch: status and plans: the WR switch is the core of any WR
network. This talk presents its internal workings in detail and
discusses the latest release of the gateware and software, along
with plans for the near future.
WR PTP core: status and plans: designs of WR nodes typically use
the WR PTP core. It is an HDL core which gets instantiated in the
node's FPGA and ensures basic interfacing with WR. This talk
provides details about the internal design, the latest release and
plans for the short-term future.
WR demo: putting together all the bits and pieces that make a WR
network, and testing timing and determinism. The demo will also
showcase the latest tools for WR network monitoring and diagnostics.
PPSi: status and plans: PPSi is the PTP stack we use in WR,
implementing the WR extensions. It is Free and Open Source and it
can run in hosted environments (such as the Linux running in the WR
switch) and in bare-metal systems (such as the soft-core CPU inside
the WR PTP core). The talk describes its basic design, the details
of the latest release and plans for the short-term future.
WR absolute calibration: On-site network calibration can be
avoided when using absolute calibrated components, which can be
freely exchanged without recalibration. Absolute calibration of
network components (i.e WR devices and electro-optical converters)
enables independent developers and/or vendors to exchange their
calibrated components while achieving absolute sub ns timing.
Absolute calibration enforces standardization.
IEEE 1588 standardisation update: A new revision of the IEEE
1588 standard is approaching publication. This new revision includes
concepts derived from WR under the "High Accuracy" denomination. In
the future, WR gear will also comply with this new revision, making
the extensions outside of the standard superfluous. We will present
the current status of the standardisation process and the plans for
the coming months.
Long Distance White Rabbit: For both the SKA and the ASTERICS
project, we study how the stability of a WR link is affected by
factors like wavelength, temperature and fiber type. The SKA is a
future radio telescope about to be constructed in semi-desert areas
in South Africa and Australia, where WR will be used for time
transfer on overhead fiber links of up to 173km. In the ASTERICS
project, we research the use of WR for long distance frequency
transfer over public fiber. We show how the WR signal can co-exists
with an existing DWDM infrastructure, and aim to get close to
H-maser performance over a link of up to 165km, to provide a
reference signal to the LOFAR and Dwingeloo radio telescopes.
Frequency & Time Performance Review of a 500km cascaded
WhiteRabbit Link: As a premise to deployment of White Rabbit over
legacy active optical telecommunication networks, we report on the
frequency stability and dissemination using the White Rabbit
technology over an in-lab cascaded unidirectional 500km fiber link
set-up. We use White Rabbit equipment improved in collaboration with
SevenSol and with support of the WR community, and show short term
frequency stability of 2·10 -12 averaging down to 4·10
-15 after 200000 s of integration time. No frequency
shift is observed within the statistical error bars.
Towards distributed fault-tolerant timekeeping based on a
WR-network: This talk will review progress and plans towards
distributed fault-tolerant timekeeping based on a White Rabbit
network of clocks. Open hardware is being developed for high
performance clock distribution, multiplexing, measurement, and
steering. Software for distributed and fault-tolerant modeling of
clocks is being developed based on a Kalman filter approach.
White Rabbit Industrial Timing Enhancement: Time signal
distribution is important both in scientific and industrial fields.
There is an increasing demand for synchronization networks that
provide precise time and frequency from telecommunication operators
building 5G mobile communication networks, the power-grid sector
that builds and utilizes smart grids and other sustainable energy
solutions, the financial sector to comply with EU regulations, and
scientific users. New techniques for Time and Frequency
dissemination on optic fiber today offer the best performance and
the highest resilience. White Rabbit Precision Time Protocol
(PTP-WR) is one of the most performing time transfer techniques,
providing sub-nanosecond accuracy, resilient and secure timing
traceable to Coordinated Universal Time (UTC). It has been
demonstrated that WR-PTP can be successfully implemented in
long-distance optical fiber links. Since June 2018, a consortium
composed of 10 institutions, NMIs, companies and academia,
coordinated by INRIM within the program EMPIR of Euramet, is taking
part in the project WRITE (White
Rabbit Industrial Timing Enhancement). During the White Rabbit
workshop, I will present the new features that will be developed to
improve the WR-PTP capabilities and to facilitate the take up at the
industrial level. These include: calibration techniques to obtain
reliable, accurate traceability; devices to improve the robustness
and resilience of PTP-WR. Moreover, some tests involving industrial
users are planned.
DMTD clock generation using FPGA internal PLLs: WR nodes
typically need to include a dedicated controllable oscillator to
generate the offset frequency used by the DMTD phase detector. This
presentation shows an alternative method in which that frequency is
internally generated in the FPGA, with no need for the additional
oscillator. This can help simplify the design of future nodes and
can also make it easier to WR-enable existing boards.
WR development and deployment for the LHAASO project: The
construction of LHAASO project has started and a quarter of the
detector array will be deployed this year. A special fan-less White
Rabbit switch has been developed based on WRS-V3.4. This talk will
give the details of the WRS-FL and its first deployment in LHAASO
site. Several other WR gears recently developed will also be briefly
White Rabbit in Financial Markets: Deutsche Börse Group
operates, amongst other things, two electronic financial markets.
Xetra, the reference market for exchange trading in German shares
and ETFs, and Eurex, a leading global derivatives exchange trading
the most liquid EUR-denominated equity index and fixed income
derivatives. This presentation explains why Deutsche Börse needs a
time synchronization technology superior than standard NTP and PTP
and how Deutsche Börse achieved their goals using White Rabbit.
White Rabbit case study: preliminary results: In this
presentation, we will discuss the preliminary results of our
research collaboration on the economics and collaborative dynamics
of Open Hardware development. Based on the case of "White Rabbit"
(WR) at CERN, we will examine the process of creating an open
platform for collaborative development involving companies, research
centers, and volunteers working with Free and Open Source projects.
Our preliminary results were obtained through a combination of
research methods, including documentary analysis, interviewing, and
a survey conducted by CERN "Knowledge Transfer" in 2016. For the
conclusion, we discuss the implications of our results and request
comments on a research report we prepared for the European
Commission "Open Science Monitor" on WR and its importance for
understanding the challenges and benefits of Open Hardware
development for the sciences.
RF distribution over WR: Timing systems in synchrotrons often
need to be referenced the RF frequency which accelerates the
particles. Phase-compensated RF distribution is also useful in other
domains such as radar. This talk presents a method for distributing
RF using WR and a distributed DDS approach, along with the current
status and plans for the short-term future.
ESRF timing system based on White Rabbit: The ESRF synchrotron
aims at providing extremely bright X rays for the study of matter at
atom level. These X rays are generated by the deviation of an
electron beam injected in a storage ring. This injection process is
managed by the timing system which has been recently refurbished by
using the White Rabbit technology and the RF distribution over WR
method. This presentation focuses on this new system, its
implementation and status.
WR eXtensions for Instrumentation (WRXI): status and plans: WR
can be used to build a "distributed oscilloscope". In order to
guarantee plug & play behaviour for the different types of gear
involved, some conventions are needed. This talk presents
WRXI, its present status
and plans for the short-term future.
On Time - In Time: Successful Operation of the GSI Facility by
White Rabbit (except UNILAC): After successful CRYRING operation
in 2017, the White Rabbit based General Machine Timing system (GMT)
is successfully applied to the retrofitted GSI facility in 2018.
This contribution gives an overview on the achievements, shares
experience and gives an outlook to the planned activities for the
WR results in 7S and the University of Granada: a presentation
made of three parts: a) Scalability and performance of the WR
protocol over large networks; b) Redundant WR technology: HSR
White-Rabbit; c) WR Timing solution for SST CTA telescopes.
Application of WR supporting the time calibration of GNSS
installations for metrological use: GNSS calibrations are based on
traveling receiver setups that are assumed to be constant with
respect to their delays. That either implies the local installation
of the traveling antenna cable or the estimation of L-band delays of
existing cables in customer installations. The former is often for
practical reasons impossible, whereas the latter is difficult and
increases uncertainties. At installations where fibers are already
deployed, WR is a viable alternative to deterministically present
the timescale to the traveling equipment. We present a possible
solution and show what challenges this implies.
The TOWR project: The objective of the TOWR (pronounced “tower”)
is the development of a time distribution service via optical fibre
over the Madrid region, based on time generation from very stable
clocks (hydrogen masers), GNSS time-transfer (including GPS and
Galileo) to UTC (k) laboratories, and White-Rabbit technology. The
activity aims at demonstrating a robust and accurate
“Time-as-a-Service” (TaaS) concept. An increasing number of
applications require accurate, reliable, and traceable signals for
time and synchronization, normally aligned to Coordinated Universal
Time (UTC). Key fields of application are banking and finance,
mobile telecommunication networks, and energy grids. The TOWR is
proposed as a pilot project for a first customer in the financial
market: the Madrid Stock Exchange (Bolsa de Madrid) covering a
distance of around 50 km.