Because accurate and secure time is essential for any computer network finding a time source that is both precise and secure, is an important part of keeping a network healthy. With network time sources, there are plenty of choices, but not all of them can provide the security and precision needed by the modern network. (more…)
Archive for the ‘GPS’ Category
The physics world got itself into a bit of a tizz this month as scientists at CERN, the European Laboratory for Particle Physics, found an anomaly on one of their experiments, which seemed to show that some particles were travelling faster than light.
Faster than light travel for any particle is prohibited of course, according to Einstein’s Special Theory of Relativity, but the OPERA team at CERN, who fired neutrinos around a particle accelerator, travelling for 730 km, found that the neutrinos travelled the distance 20 parts per million faster than photons (light particles) meaning they broke Einstein’s speed limit.
While this experiment could prove to be one of the most important discoveries in physics, physicists are remaining sceptical, suggesting that a cause could be an error generated in the difficulties and complexities of measuring such high speeds and distances.
The team at CERN used GPS time servers, portable atomic clocks and GPS positioning systems to make their calculations, which all provided accuracy in distance to within 20cm and an accuracy of time to within 10 nanoseconds. However, the facility is underground and the GPS signals and other data streams had to be cabled down to the experiment, a latency the team are confident they took into account during their calculations.
Physicists from other organisations are now attempting to repeat the experiments to see if they get the same results. Whatever the outcome, this type of groundbreaking research is only possible thanks to the accuracy of atomic clocks that are able to measure time to millionths of a second.
To synchronise a computer network to an atomic clock you don’t need to have access to a physics laboratory like CERN as simple NTP time servers like Galleons NTS 6001 will receive an accurate source of atomic clock time and keep all hardware on a network to within a few milliseconds of it.
Accurate time is one of the most important aspects to keeping a computer network secure and safe. Places such as stock exchanges, banks and air traffic control rely on secure and accurate time. As computers rely on time as their only reference for when events happen, a slight error in a time code could lead to all sorts of errors, from millions being wiped off share prices to aeroplane flight paths being incorrect.
And time doesn’t just need to be accurate for these organizations, but secure too. A malicious user who interferes with a timestamp could cause all sorts of trouble, so ensuring time sources are both secure and accurate is vital.
Security is increasingly important for all sorts of organisations. With so much trade and communication conducted over the internet, using a source of accurate and secure time is as important a part of network security as anti-virus and firewall protection.
Despite the need for accuracy and security, many computer networks still rely on online time servers. Internet sources of time are not only unreliable, with inaccuracies commonplace, and distance and latency affecting the precision, but an Internet time server is also unsecure and able to be hijacked by malicious users.
But an accurate, reliable and completely secure source of time is available everywhere, 365 days a year—GPS.
While commonly thought of as a means of navigation, GPS actually provides an atomic clock time code, direct from the satellite signals. It is this time code that navigation systems use for calculating position but it is just as effective to provide a secure time stamp for a computer network.
Organizations that rely on accurate time for safety and security all use GPS, as it is a continuous signal, that never goes down, is always accurate and can’t be interfered with by third parties.
To utilise GPS as a source of time, all that is required is a GPS time server. Using an antenna, the time server receives the GPS signal, while NTP (Network Time Protocol) distributes it around the network.
With a GPS time server, a computer network is able to maintain accuracy to within a few milliseconds of the atomic clock time signal, which is translated into UTC time (Coordinated Universal Time) thanks to NTP, ensuring the network is running the same accurate time as other networks also synchronised to a UTC time source.
The argument about the use of the Leap Second continues to rumble on with astronomers again calling for the abolition of this chronological ‘fudge.’
The Leap Second is added to Coordinated Universal Time to ensure the global time, coincides with the movement of the Earth. The problems occur because modern atomic clocks are far more precise than the rotation of the planet, which varies minutely in the length of a day, and is gradually slowing down, albeit minutely.
Because of the differences in time of the Earth’s spin and the true time told by atomic clocks, occasional seconds need adding to the global timescale UTC—Leap Seconds. However, for astronomers, leap seconds are a nuisance as they need to keep track of both the Earth’s spin—astronomical time—to keep their telescopes fixed on studied objects, and UTC, which they need as atomic clock source to work out the true astronomical time.
Next year, however, a group of astronomical scientists and engineers, plan to draw attention to the forced nature of Leap Seconds at the World Radiocommunication Conference. They say that as the drift caused by not including leap seconds would take such a long time—probably over a millennia, to have any visible effect on the day, with noon gradually shifting to afternoon, there is little need for Leap Seconds.
Whether Leap Seconds remain or not, getting an accurate source of UTC time is essential for many modern technologies. With a global economy and so much trade conducted online, over continents, ensuring a single time source prevents the problems different time-zones could cause.
Making sure everybody’s clock reads the same time is also important and with many technologies millisecond accuracy to UTC is vital—such as air traffic control and international stock markets.
NTP time servers such as Galleon’s NTS 6001 GPS, which can provide millisecond accuracy using the highly precise and secure GPS signal, enable technologies and computer networks to function in perfect synchronicity to UTC, securely and without error.
The launch date for the first Galileo satellites, the European version of the Global Positioning System (GPS), has been scheduled for mid October, say the European Space Agency (ESA).
Two Galileo in-orbit validation (IOV) satellites will be launched using a modified Russian Soyus rocket this October, marking a milestone in the Galileo project’s development.
Originally scheduled for August, the delayed October launch will lift off from ESA’s spaceport in French Guiana, South America, using the latest version of the Soyuz rocket—the world’s most reliable and most used rocket in history(Soyus was the rocket that propelled both Sputnik—the first orbital satellite—and Yuri Gargarin—the first man in orbit—into space).
Galileo, a joint European initiative, is set to rival the American controlled GPS, which is controlled by the United States military. With so many technologies reliant on satellite navigation and timing signals, Europe needs its own system in case the USA decides to switch off their civilian signal during times of emergency (war and terrorist attacks such as 9/11) leaving many technologies without the crucial GPS signal.
Currently GPS not only controls the words transportation syste3ms with shipping, airliners and motorists increasingly becoming reliant on it, but GPS also provides timing signals to technologies such as NTP servers, ensuring accurate and precise time.
And the Galileo system will be good for current GPS users too, as it will be interoperable and, therefore, will increase accuracy of the 30-year-old GPS network, which is in need of upgrade.
Currently, a prototype Galileo satellite, GIOVE-B, is in orbit and has been functioning perfectly for the last three years. Onboard the satellite, as with all global navigation satellite system (GNSS) including GPS, is an atomic clock, which is used to transmit a timing signal that Earth-based navigation systems can use to triangulate accurate positioning (by using multiple satellite signals).
The atomic clock aboard GIOVE-B is currently the most accurate atomic clock in orbit, and with similar technology intended for all Galileo satellite, this is the reason why the European system will be more accurate than GPS.
These atomic clock systems are also used by NTP servers, to receive an accurate and precise form of time, which many technologies are dependent on to ensure synchronicity and accuracy, including most of the world’s computer networks.
Global time synchronisation may seem like a modern need, we do after all live in a global economy. With the internet, global financial markets and computer networks separated by oceans and continents—keeping everybody running in synchronisation is a crucial aspect of the modern world.
Yet, a need for global synchronicity began a lot earlier than the computer age. International standardisation of weights and measures began after the French revolution when the decimal system was introduced and a platinum rod and weight representing the metre and the kilogram were installed in the Archives de la République in Paris.
Paris eventually became the central head of the International System of Units, which was fine for weights and measures, as representatives from different countries could visit the vaults to calibrate their own base measurements; however, when it came to standardising time, with the increased use of transatlantic travel following the steamer, and then the aeroplane, things became tricky.
Back then, the only clocks were mechanical and pendulum driven. Not only would the base clock that was situated in Paris drift on a daily basis, but any traveller from the other side of the world wanting to synchronise to it, would have to visit Paris, check the time on the vault’s clock, and then carry their own clock back across the Atlantic—inevitable arriving with a clock that had drifted perhaps several minutes by the time the clock arrived back.
With the invention of the electronic clock, the aeroplane and transatlantic telephones, things became easier; however, even electronic clocks can drift several seconds in a day so the situation wasn’t perfect.
These days, thanks to the invention of the atomic clock, the SI standard of time (UTC: Coordinated Universal Time) has so little drift even a 100,000 years wouldn’t see the clock lose a second. And synchronising to UTC couldn’t be simpler no matter where you are in the world—thanks to NTP (Network Time Protocol) and NTP servers.
Now using GPS signals or transmissions put out by organisations like NIST (National Institute for Standards and Time-WVBB broadcast) and NPL (National Physical Laboratory—MSF broadcast) and using NTP servers, ensuring you are synchronised to UTC is simple.
NTP servers like Galleon’s NTS 6001 GPS receive a atomic clock time signal and distributes it around a network keeping every device to within a few milliseconds of UTC.
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.
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.
Since the Global Positioning System (GPS) first became available for civilian use in the early 1990’s, it has become one of the most commonly used modern pieces of technology. Millions of motorists use satellite navigation, while shipping and airline industries are heavily dependent on it.
And its not just wayfinding that we use GPS for, many technologies from computer network to traffic lights, to CCTV cameras, use the GPS satellite transmissions as a method of controlling time—using the onboard atomic clocks to synchronise these technologies together.
While plenty of advantages to using GPS for both navigation and time synchronisation exist, it’s accurate in both time and positioning and is available, literally everywhere on the planet with a clear view to the sky. However, a recent report by the Royal Academy of Engineering this month has warned that the UK is becoming dangerously dependent on the USA run GPS system.
The report suggests that with so much of our technology now reliant on GPS such as road, rail and shipping equipment, there is a possibility that any loss in GPS signal could lead to loss of life.
And GPS is vulnerable to failure. Not only can GPS satellites be knocked out by solar flares and other cosmological phenomenon, but GPS signals can be blocked by accidental interference or even deliberate jamming.
If the GPS system does fail then navigation systems could become inaccurate leading to accidents, however, for technologies that use GPS as a timing signal, and these range from important systems at air traffic control, to the average business computer network, then fortunately, things should not be that disastrous.
This is because GPS time servers that receive the satellite’s signal use NTP (Network Time Protocol). NTP is the protocol that distributes the GPS time signal around a network, adjusting the system clocks on all the devices on the network to ensure they are synchronised. However, if the signal is lost, then NTP can still remain accurate, calculating the best average of the system clocks. Consequently if the GPS signal does go down, computers can still remain accurate to within a second for several days.
For critical systems, however, where extremely precise time is required constantly, dual NTP time servers are commonly used. Dual time servers not only receive a signal from GPS, but also can pick-up the time standard radio transmissions broadcast by organisations such as NPL or NIST.
When we want to know the time it is very simple to look at a clock, watch or one of the myriad devices that display the time such as our mobile phones or computers. But when it comes to setting the time, we rely on the internet, speaking clock or somebody else watch; however, how do we know these clocks are right, and who is it that ensures that time is accurate at all?
Traditionally we have based time on Earth in relation to the rotation of the planet—24 hours in a day, and each hour split into minutes and seconds. But, when atomic clocks were developed in the 1950’s it soon became apparent that the Earth was not a reliable chronometer and that the length of a day varies.
In the modern world, with global communications and technologies such as GPS and the internet, accurate time is highly important so ensuring that there is a timescale that is kept truly accurate is important, but who is it that controls global time, and how accurate is it, really?
Global time is known as UTC—coordinated Universal Time. It is based on the time told by atomic clocks but makes allowances for the inaccuracy of the Earth’s spin by having occasional leap seconds added to UTC to ensure we don’t get into a position where time drifts and ends up having no relation to the daylight or night time (so midnight is always at day and noon is in the day).
UTC is governed by a constellation of scientists and atomic clocks all across the globe. This is done for political reasons so no one country has complete control over the global timescale. In the USA, the National Institute for Standards and Time (NIST), helps govern UTC and broadcast a UTC time signal from Fort Collins in Colorado.
While in the UK, the National Physical Laboratory (NPL) does the same thing and transmits their UTC signal from Cumbria, England. Other physics labs across the world have similar signals and it is these laboratories that ensure UTC is always accurate.
For modern technologies and computer networks, these UTC transmissions enable computer systems across the globe to be synchronised together. The software NTP (Network Time Protocol) is used to distribute these time signals to each machine, ensuring perfect synchronicity, while NTP time servers can receive the radio signals broadcast by the physics laboratories.