The entire world, more or less, and certainly every continent, is linked to the World Wide Web. So how does data make its way from major data centers in each country across vast oceans and around the globe?
With our new AlohaNAP data center and interconnection facility, located in Hawaii, debuting this week at the PTC’15 conference, we’re taking a closer look at the technology that drives fiber communications beneath the waves. AlohaNAP has a unique feature for a data center: satellite dishes, which offer another method of intercontinental communications, should fiber access experience troubles.
Undersea Fiber Cables
Kapolei, HI is linked to the rest of the world through submarine fiber optic cables, which carry internet and telephone traffic under the ocean between mainland continents. The first trans-pacific cables were laid in 1902, though the first submarine cables ever installed were submersed in the 1850s. These were, of course, telegraph cables.
Today’s cables are capable of speeds in the terabits per second. They consist of eight layers of protective material and communication mediums, including plastic, mylar, steel, copper, petroleum jelly, and optic cables. These layers are necessary to avoid damage that results from decay over time, wildlife, and the force of the ocean itself. Some cables have thicker casing near land, as ships can sever them accidentally—or, in the case of international conflict, on purpose!
Fiber lines send signals through colors and pulses of light, which are encoded and decoded at either end by transmitters and converters, which turn it back into an electrical signal that can be interpreted by computers. Under the ocean, fiber optic repeaters receive and re-transmit light signals about every hundred kilometers to avoid distortion and data loss.
There are dozens of fiber lines criss-crossing each ocean. One of the most important cables in Oahu is the Southern Cross, but eight different networks pass through the island.
Recent headlines about Elon Musk and Richard Branson pursuing large arrays of tiny internet satellites are evidence that this method of connecting to the internet is only just starting to take off.
Satellite connectivity has been a reality for decades but the latency issues at hand have kept it from becoming the primary method, even with the high costs of laying fiber. However, satellites are acceptable for applications without major latency restrictions. They can also serve as a backup connection, should fiber lines be cut or service interrupted by some other method, and they also broadcast signals into remote and under-served areas of the globe.
Satellite internet connections have a maximum connection rate (download) of about 1000 Mbps, or 1 Gbps—slow when compared to fiber’s terabits per second. The average latency of 638 ms is what really kills satellite. However, satellite internet can provide all the services that fiber can, with perhaps the exception of reliable streaming video.
New satellite networks are being constructed at lower orbits to provide faster connectivity. These networks have reached well over 1 Gbps and latencies of 7 ms. Soon, satellite could be a viable alternative to fiber for far-flung areas on the planet.
Satellites optimized for broadband connections shoot spot beams, rather than broad beams previously used. This leads to higher bandwidth capacity and increased performance. Satellites are made up of two main components: the payload, which houses the communication equipment, and the bus, which has all additional equipment, like pieces to move the satellite into position, power supplies, and tracking information.
The AlohaNAP facility has eight satellites operating in the C and KU bands, capable of reaching the Americas and as far west as Saudi Arabia.