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'Smartening up' submarine communication cables
Nov. 3, 2014
by Mark Ollig

More than 550,000 miles of submarine cables currently provide telecommunication and Internet services between most of the world’s continents.

The first undersea or submarine cable began providing telegraph service between Dover, England and Calais, France Oct. 17, 1851.

By 2015, there will be some 285 working submarine cables originating from land-based stations on one continent, crisscrossing oceans and seas, and terminating to land-based stations located in other continents, or regions of the world.

The importance of these submarine cables cannot be overstated; they are used by scientists, health facilities, educators, governments, and citizens of the world.

They also provide the pathways of commerce for many global businesses.

These undersea cables furnish the physical venue, or “pipe” for communicating the social narratives and political ideals, for millions – if not billions – of people around the world.

Most of these physical cables are providing their service, while silently resting on the bottom of the sea, or ocean floor.

The longest undersea fiber-optic cable; named the South-East Asia Middle-East-Western Europe 3 (SEA-ME-WE 3), covers 24,000 miles, and includes 39 separate landing points where the cable comes onto dry land.

Besides providing communications and Internet, a recent report is recommending ocean monitoring technology be added onto submarine cables.

In a 40-page report, a joint task force of agencies proposed new uses for submarine cables.

This report addresses “The scientific and societal case for the integration of environmental sensors into new submarine telecommunication cables.”

Many telecom companies and operators of submarine fiber-optic cables, currently monitor the electrical and optical power traveling inside those cables.

Whenever a cable is cut or becomes degraded, the measurements monitored can provide an accurate location of where the disruption is, allowing a submarine cable repair ship to be quickly dispatched to perform restorations.

The report suggests these underwater cables be equipped with sensory devices, which would provide detailed information about their watery surroundings.

Some of the information obtained could include measurements of ocean currents and ground vibrations, using attached accelerometer sensor devices.

By monitoring the ocean’s water pressure, temperature, and other conditions via sensors fastened to a network of submarine cables, weather bureaus and other agencies would be able to obtain immediate information, thus providing advanced warning to nearby coastal regions which could be affected by tsunamis, for example.

Environmental accelerometers, seismometers, pressure gauges, and other sensor devices could be installed on special ports inside the submarine fiber-optic cable repeaters.

These repeaters boost the cables power and signal strength over long distances.

Some fiber-optic submarine cable repeater units are attached every 25 to 100 miles, and get their power from the fiber cable’s copper tubing. This tubing is encased within the same protective steel “strength members” which wrap around the optical fibers.

Specific sensors installed would notify appropriate agencies in the event of earthquakes, landslides, and changes in water quality.

The communication requirements for these sensors are estimated to use a minute amount of bandwidth, and a data rate of less than 20 kilobit per second (kb/s).

Information could be monitored regarding worldwide sea-levels, and the heat exchange between the oceans and the atmosphere.

Non-environmental hazards, such as a ship’s fishing net or anchor dragging a submarine cable out of place, could also be detected.

Today, we are using floating oceanic buoys, earth-orbiting satellites, and ships at sea to gather information about the oceans; however, not enough deep-sea, real-time data is being obtained from the ocean floor.

Many of the world’s submarine cables will be replaced within the next 30 years, so the case is being made for the “greening” of future submarine fiber-optic cables, with real-time sensor-monitoring technology, which would last the expected 25-year lifetime of the new cables.

Submarine cables have the potential to become, as this report states; “a principal vantage point for keeping active watch over the Earth’s ocean environment.”

The report is very detailed, and contains many drawings, charts, photographs, and source links.

The research was conducted by the International Telecommunication Union (ITU), the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization (UNESCO/IOC), and the World Meteorological Organization (WMO).

The complete report can be read at http://tinyurl.com/q2u67or.

My Winsted readers might be interested to know, in the late 1960s, a submarine cable was placed along the bottom of Winsted Lake by the local telephone company.

A pontoon boat containing the large wooden reel holding the submarine cable, along with the telephone company crew, slowly made its way across the lake, traveling west to east.

As the submarine cable was pulled from the reel, heavy steel bolts were strapped onto it about every 10 feet, which weighed down the cable as it was slowly lowered into the murky depths of Winsted’s most famous body of water.

For many years, this submarine cable reliably provided telecommunications service from the telephone company’s downtown central office, to the subscribers located on the east side of the lake.


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