Work begins to repair severed net

Work has begun to repair two damaged internet cables in the Mediterranean Sea that were severed last week.

Flag Telecom, one of the firms responsible for the cables, says it will take about a week to be fixed.

The break in cables has caused disruption to net services in the Middle East and India. The cause is still not known.

Repairs will involve a team of about 50 people, including navigation experts and cable engineers, said Flag Telecom.

The ship that will repair the first severed cable is already in place, with repairs underway, while the second vessel is expected to begin work on Tuesday.

Bespoke ships

"It will be a highly technical job and should take a week to complete," a spokesperson for Flag Telecom told the BBC News website.

The cause of the damage has not been officially confirmed but there have been reports that the breaks were related to a tanker dragging its anchor along the sea bed.

However, the Egyptian communications ministry has denied any ships were in the area at the time of the break.

The first job in such a situation was to find the exact location of the damaged cable, said Mark Harper, manager of cable system support at Cable and Wireless.

The firm is not involved in the repair operation, but has carried out similar work in the past.

Often the location of a break can be found by cable engineers back on shore. The areas affected by the outage will give key clues as to what part of the cable is broken.

To get a more precise location, cable engineers can send light pulses along the fibres in the cable using a device known as a Optical Time Domain Reflectometer.

When the pulses hit the broken part of the cable they will bounce back and by measuring the time it takes for them to return, engineers can ascertain the location of the damage to within tens of metres.

The next stage is to employ a specially fitted cable ship, which will have onboard remotely operated vehicles (ROVs).

Fishing

If the ROV is able to locate the cable it can cut out the non-working sections and pull the cable back onto the ship.

Alternatively a device onboard known as a grapnel can hook the cable from the sea floor and drag it on to the ship.

"The first option is preferable because it means you can recover the cable very close to the end whereas a grapnel is less precise," said Mr Harper.

Grapnels have been in use for hundreds of years, and so were part of the equipment employed when the first telegraph cables were laid.

The damaged cable can be repaired on the ship at which point a technician will splice new cable to the existing pieces.

Once repaired it can be lowered back to the seabed.

Two cable operators were involved in this most recent outage.

FLAG Telecoms, which has responsibility for the Fiber-Optic Link Around the Globe (FLAG), a 28,000km (17,400 mile) long submarine communications cable and SEA-ME-WE 4, or the South East Asia-Middle East-West Europe 4 project - which links South East Asia to Europe via the Indian subcontinent and the Middle East.

There was disruption to 70% of the nationwide network in Egypt, and India suffered up to 60% disruption.

Disruption also occurred in the United Arab Emirates (UAE), Kuwait and Saudi Arabia, reported the Associated Press.

In Dubai, at least two internet service providers (ISPs) were affected.

In December 2006, seven of the eight cables connected to Taiwan were damaged by an earthquake, disrupting communications in much of Asia.

These cables took several months to fully repair.

Natural disasters are one of several causes of cable outages.

In this case, an errant anchor has been blamed and Mr Harper believes there is "still a partial conflict between the needs of shipping and of telecoms".

But it is not the biggest problem facing cable operators.

"Fishing is still the biggest issue. Historically in Europe trawler fishing has been a problem although in the last 15 years most cables have been buried in the seabed to overcome this," said Mr Harper.

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Switching on the digital world

Sixty years ago two scientists would start a month of experiments that would come to shape the modern world.

The period of work by John Bardeen and Walter Brattain, working under William Shockley, would become known as the "miracle month" and resulted in the world's first working transistor.

"They demonstrated something that became the basic mechanism for our entire electronic industry," said Dr Art Ramirez of Bell Labs, the location of the 1947 invention.

"They're in aircraft, automobiles, digital cameras and microwave ovens," said Jeff Katz, a guide at the Computer History Museum in Silicon Valley.

"In every house there is somewhere in the region of 50 to 100 million transistors, and that's probably a conservative estimate," he said. "If you start including computers and digital cameras you are probably approaching one trillion."

Computing age

Transistors are used to control the flow of electricity in a circuit.

The flow between two terminals - the source and the drain - is controlled by applying a current or voltage to the third terminal - the gate.

"It's very much like a water faucet. The gate is the handle and the faucet controls the flow of electrons between the source and the drain," said Dr Ramirez.

The tiny devices have two key properties which make them attractive to electronics engineers: they can amplify a signal and they can act like a switch.

This ability to boost a signal makes them attractive to the communications and broadcast industry whilst their capability to turn on and off quickly has made them the component of choice for computation.

Their development came from a world recovering from the Second World War.

"During the war there was a lot of electronics work going on for communications and computation mainly for military purposes," said Mr Katz.

For example, in December 1943, the British built Colossus - the first electronic computer - to break messages passed by the German high command.

"This culminated in the invention of the ENIAC computer," said Mr Katz.

The ENIAC was installed at the University of Pennsylvania in 1946 and was the first large-scale programmable digital computer.

Like Colossus, instead of transistors it used vacuum tubes, also known as thermionic valves, which were delicate structures that looked similar to light bulbs.

"It filled a room, the power consumption was huge, it had nearly 18,000 tubes but it had very, very limited functionality," said George Scalise president of the Semiconductor Industry Association (SIA).

"There was no way of scaling up the computer without finding some way to make the devices that allowed it to function lower cost, lower power, smaller and more reliable."

Crude device

As a result scientists across the world began to look for an alternative.

One of the leading groups was based at the Bell Telephone Laboratories in New Jersey.

The Sonotone 1010 was the first transistorised product

There, a theoretician known as William Shockley led the solid state physics group, which included other scientists such as John Bardeen and Walter Brattain.

After hiring Bardeen, Shockley set him off on a project to understand the interaction of electrons on the surfaces of semiconductors, but personal differences meant the new recruit soon went his own way.

"Bardeen really didn't get along with Shockley so he started working with Brattain who was an experimentalist," said Dr Ramirez.

Over 18 months the pair went about investigating these "surface states" using various experimental set-ups.

"It was a series of experiments that led to a deeper understanding of how to build a device that actually switched," he said.

The work led to their miracle month and culminated with them showing off the first working transistor two days before Christmas in 1947.

The half-inch (1.25cm) device, made from germanium with two gold contacts held in place by a plastic wedge, bore little resemblance to the tiny precise switches produced today.

"I have seen a replica been made of the first transistor in the same way as it was made and it's remarkably crude," said Mr Katz.

However, it was enough to convince the hierarchy of Bell Labs and after filing patents it was announced to the public on 1 July 1948

"This was announced to fantastic fanfare," said Dr Ramirez. "Reading about it reminds me of the way that Steve Jobs rolls out the iPod."

Silicon block

Over the next few years, Shockley modified the design of the transistor into a device closer to the design used today.

"He made such a key contribution that he was a co-recipient of the Nobel Prize [for Physics] in 1956," said Dr Ramirez.

With the invention of the transistor many new applications become possible, including the first transistor-based hearing aid, made by Sonotone This was followed by the first mass market device - the transistor radio.

"They were about the size of a paperback book today but the replaced something that was about the size of a bread toaster," said Mr Katz.

They were also used for military equipment, televisions and in communications networks.

Initially, transistors were built separately and then wired together to make circuits.

But in 1958, Jack Kilby, a scientist at Texas Instruments, invented the integrated circuit, a circuit where all of the components were built onto a single block of material, commonly silicon.

The transistor had found its natural home and its development has continued ever since.

Elements that used to be measured in millimetres and even centimetres in the first device are now measured in nanometres (billionths of a metre).

Intel's next generation of chip, for example will pack more than four hundred million transistors into an area the size of a postage stamp.

The silicon industry is now worth almost $300bn a year and plays a key role in almost every area of life from computing and health care to entertainment and global communications.

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The Tech Lab: Vint Cerf

News services Vint Cerf is known as one of the founder fathers of the internet and played a key role in the development of the protocols which underpin the global net. He was a founding member of the Internet Society and is Google's Chief Internet Evangelist.

Vint Cerf is one of the leading figures in the internet's development

If we look at other innovative technologies that fundamentally transformed human communications - the printing press, the telephone and television, to name a few - we are confronted with the fact that it takes generations for their full effects to be understood.

The internet, by comparison, has only existed for three decades, and the World Wide Web is younger still.

The internet, however, stands poised to become the greatest communications platform humanity has ever known. It has profoundly increased access to information around the world, and it has likewise provided a platform for free expression on a scale unimaginable a generation ago.

For a variety of reasons - cultural, political, technological - the internet has grown rapidly.

The benefits it offers and the degree to which we rely on it (for everything from personal communications to global financial transactions), far outstrip its relatively short existence.

As access to the internet spreads to more and more places around the world, more people will come online; they'll access the net through a wider variety of devices, and they'll produce and consume new types of content.

The continued expansion of the internet poses very real challenges to those of us responsible for its health.

Key infrastructure

The robustness and security of the internet will climb in importance as we rely increasingly on it and its services.

Improving the resilience and resistance to attack of key infrastructure such as the Domain Name System (the phone book of the internet) and the routing system will be major focal points for near-term internet development.

Introducing DNSSEC (security for the Domain Name System) and the digital signing of address space by the Regional Internet Registries will assume much higher priority.

Internet-based software and digital goods have historically been vulnerable to various kinds of failures and subject to a variety of attacks. The computer science community is challenged to devise solutions to these problems.

Capacity poses a further challenge to the future of the web. As more devices become part of the internet (think of the three billion mobile phones already in operation), we will need to move to a new internet address space, called IPv6.

With its 128 bits of address space (about 340 trillion trillion trillion addresses), there will be ample address space for the foreseeable future.

It will be a non-trivial exercise to bring IPv6 online in parallel with the present IPv4 system and it is not too early to get started. Efforts in Japan and China have begun blazing trails towards this important new goal.

Stunningly valuable

Going forward, we must also remain aware of limitations of the data we access through the internet. Information on the web varies in quality from completely useless or even damaging to stunningly valuable.

Today's search engines draw the most relevant information to our attention, and as more data become available online, the importance of search engines will only increase. In the future, people around the world will likely look for new ways to identify the authenticity of online information sources.

The idea that all the world's knowledge could be discoverable not just by humans but by programs acting on their behalf at speeds well beyond the superhuman, is one of this century's most exciting opportunities

We will also be confronted with a kind of "information decay" in which digital objects become less and less accessible owing to the age of the software that created it.

As an example: it is already a challenge to watch videos posted on the BBC website in 1997.

Imagine trying to watch the same video in 100 years. Or in one thousand years.

It's not only file formats that change, though. Changes in computer programs, operating systems and even the hardware that we use to build computers will accentuate the challenge of keeping digital information meaningful.

This raises a host of intellectual property questions that will almost certainly need to be considered.

Prosaic opportunities

From a strictly technological standpoint, then, the future of the internet poses a number of challenges to computer scientists. The future of the net also poses opportunities for society as a whole.

Some of these opportunities are prosaic. With home, car and office appliances all online and rich sensor networks as part of the landscape of the internet, it is easy to predict that people will be looking for online services to manage these devices and systems, regardless of where they happen to be.

We have barely begun what will no doubt be a long journey, but already the openness of the web is fostering free expression in parts of the world that need it most

It is clear that programmable mobiles have the potential to become general purpose "controllers" that allow us to interact, possibly indirectly through online services, with the many devices that service us from moment to moment.

The internet is a medium for communicating information, and by democratising access to information the internet is changing people's lives for the better.

We have barely begun what will no doubt be a long journey, but already the openness of the web is fostering free expression in parts of the world that need it most.

There are challenges and setbacks along the way, but the trend is clear and inexorable. At the same time, access to information is expanding rapidly.

Usage spike

When Google News for mobile devices became available in French, the biggest spike in usage outside France was in Cte d'Ivoire.

In the developing world especially, the proliferation of mobile devices and improvements in the ability of those devices to access the web will accelerate access to information.

Every year, humanity produces more data, and we must decide how that data will be found, shared, remembered, and interpreted. As we become better able to cope with huge quantities of information, scientific and otherwise, our appetites for organising and mining it will increase.

We have already witnessed the salient benefits of shared scientific databases such as the online human genome archives.

The idea that all the world's knowledge could be discoverable not just by humans but by programs acting on their behalf at speeds well beyond the superhuman, is one of this century's most exciting opportunities, especially as much of this information may lead to medical understanding and breakthroughs.

As we deepen our understanding of our biology - the move from genetics to epigenetics and the proteome - our understanding of ourselves and the universe around us will deepen.

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