Archive for April, 2011

Japan Loses Atomic Clock Signal after Quakes

Thursday, April 28th, 2011

Having suffered earthquakes, a catastrophic tsunami, and a nuclear accident, Japan has had a terrible start to the year. Now, weeks after these terrible incidents, Japan is recovering, rebuilding their damaged infrastructure and trying to contain the emergencies at their stricken nuclear power plants.

But to add insult t injury, many of the Japanese technologies that rely on an accurate atomic clock signals are starting to drift, leading to problems with synchronisation. Like in the UK, Japan’s National Institute of Information, Communications and Technology broadcast an atomic clock time standard by radio signal.

Japan has two signals, but many Japanese NTP servers rely on the signal broadcast from mount Otakadoya, which is located 16 kilometres from the stricken Daiichi power station in Fukushima, and falls within the 20 km exclusion zone imposed when the plant started leaking.

The consequence is that technicians have been unable to attend to the time signal. According to the National Institute of Information, Communications, and Technology, which usually transmits the 40-kilohertz signal, broadcasts ceased a day after the massive Tohoku earthquake struck the region on 11 March. Officials at the institute said they have no idea when service might resume.

Radio signals that broadcast time standards can be susceptible to problems of this nature. These signals often experience outages for repair and maintenance, and the signals can be prone to interference.

As more and more technologies, rely on atomic clock timing, including most computer networks, this susceptibility can cause a lot of apprehension amongst technology managers and network administrators.

Fortunately, a less vulnerable system of receiving time standards is available that is just as accurate and is based on atomic clock time—GPS.

The Global Positioning System, commonly used for satellite navigation, contains atomic clock time information used to calculate positioning. These time signals are available everywhere on the planet with a view of the sky, and as it is space-based, the GPS signal is not susceptible to outages and incidents such as in Fukushima.


Importance of Time Synchronisation when Working in the Cloud

Wednesday, April 20th, 2011

Cloud computing has been foreseen as being the next big step in the development of information technology with more and more businesses and IT networks becoming cloud reliant and doing away with traditional methods.

The term ‘Cloud Computing’ refers to the use of on demand programs and services online including the storing of information over the internet, and using applications not installed on host machines.

Cloud computing mean that users no longer need to own, install and run software in individual machines, and doesn’t require large capacity storage. It also allows remote computing, enabling users to use the same services, work on the same documents, or access the network at any workstation able to log onto the cloud service.

While these advantages are appealing to businesses enabling them to lower IT costs while providing the same network capabilities, there are disadvantages to cloud computing.

Firstly, to work on the cloud you are reliant on a working network connection. If there is a problem with the line, whether in your locale or with the cloud service provider, you can’t work—even offline.

Secondly, peripherals such as printers and back up drives may not work properly on a cloud-orientated machine, and if you are using a non-specified computer, you won’t be able to access any network hardware unless the specific drivers and software are installed on the machine.

Lack of control is another issue. Being part of a cloud service means that you have to adhere to the terms and conditions of the cloud host, which may affect all sorts of issues such as data ownership and the number of users that can access the system.

Time synchronisation is essential for cloud services, with precise and accurate time needed to ensure that every device that connects to the cloud is logged accurately. Failure to ensure precise time could lead to data getting lost or the wrong version of a job overriding new versions.

To ensure precise time for cloud services, NTP time servers, receiving the time from an atomic clock, are used to maintain accurate and reliable time. A cloud service will essentially be governed by an atomic clock once it is synchronised to an NTP server, so no matter where users are in the world, the cloud service can ensure the correct time is logged preventing data loss and errors.

Galleon NTP server

Importance of the GPS Antenna

Monday, April 11th, 2011

The global positing system is one of the most used technologies in the modern world. So many people rely on the network for either satellite navigation or time synchronisation. The majority of road users now rely on some form of GPS or mobile phone navigation, and professional drivers are almost completely reliant on them.

And its not just navigation that GPS is useful for. Because GPS satellites contain atomic clocks—it is the time signals these clocks put out that are used by satellite navigation systems to accurately work out positioning—they are used as a primary source of time for a whole host of time sensitive technologies.

Traffic lights, CCTV networks, ATM machines and modern computer networks all need accurate sources of time to avoid drift and to ensure synchronicity.  Most modern technologies, such as computers, do contain internal time pieces but these are only simple quartz oscillators (similar type of clock as used in modern watches) and they can drift. Not only does this lead to the time slowly becoming inaccurate, when devices are hooked up together this drifting can leave machines unable to cooperate as each device may have  a different time.

This is where the GPS network comes in, as unlike other forms of accurate time sources, GPS is available anywhere on the planet, is secure (for a computer network it is received externally to the firewall) and incredibly accurate, but GPS does have one distinct disadvantage.

While available everywhere on the planet, the GPS signal is pretty weak and to obtain a signal, whether for time synchronisation or for navigation, a clear view of the sky is needed. For this reason, the GPS antenna is fundamental in ensuring you get a good quality signal.

As the GPS antenna has to go outdoors, it’s important that it s not only waterproof, able to operate in the rain and other weather elements, but also resistant to the variation in temperatures experienced throughout the year.

One of the leading causes of GPS NTP server failure (the time servers that receive GPS time signals and distribute them around a network using Network Time Protocol) is a failed or failing antenna, so ensuring you GPS antenna is waterproof, and resistant to seasonal temperature changes can eliminate the risk of future time signal failures.

Waterproof GPS Antenna

Most Accurate Atomic Clock Yet

Wednesday, April 6th, 2011

A new atomic clock as accurate as any produced has been developed by the University of Tokyo which is so accurate it can measure differences in Earth’s gravitational field—reports the journal Nature Photonics.

While atomic clocks are highly accurate, and are used to define the international timescale UTC (Coordinated Universal Time), which many computer networks rely on to synchronise their NTP servers to, they are finite in their accuracy.

Atomic clock use the oscillations of atoms emitted during the change between two energy states, but currently they are limited by the Dick effect, where noise and interference generated by the lasers used to read the frequency of the clock, gradually affect the time.

The new optical lattice clocks, developed by Professor Hidetoshi Katori and his team at the University of Tokyo, get around this problem by trapping the oscillating atoms in an optical lattice produced by a laser field. This makes the clock extremely stable, and incredibly accurate.

Indeed the clock is so accurate Professor Katori and his team suggest that not only could it man future GPS systems become accurate to within a couple of inches, but can also measure the difference in the gravitation of the Earth.

As discovered by Einstein in his Special and General Theories of Relativity, time is affected by the strength of gravitational fields. The stronger the gravity of a body, the more time and space is bent, slowing down time.

Professor Katori and his team suggest that this means their clocks could be used to find oil deposits below the Earth, as oil is a lower density, and therefore has a weaker gravity than rock.

Despite the Dick Effect, traditional atomic clocks currently used to govern UTC and to synchronise computer networks via NTP time servers, are still highly accurate and will not drift by a second in over 100,000 years, still accurate enough for the majority of precise time requirements.

However, a century ago the most accurate clock available was an electronic quartz clock that would drift by a second a day, but as technology developed more and more accurate time pieces were required, so in the future, it is highly possible that these new generation of atomic clocks will be the norm.