Telecommunications Basics, Issue 1: Warp Speed
Q. Telecommunications have evolved considerably in the last years. We see them changing our world every day. How does Internet speed evolve? What is the speed limit for users and ISP’s?Answer.To begin with, let us know that the unit to measure broadband speed -which is internet speed- is the “Bit”. (let us not think “Bit” is the same as “Byte”, which is a storage unit). One bit is either a “1″ or a “0″. This means fundamentally that there is a moment that an electrical signal is sent or not. Commonly the bits are transmitted from one point to another in “packages”. These packages are the digitalized information that communicates us with the world through internet. It can be voice, e-mail, video, music, etc. They are all narrowed down to thousands and thousands of 1′s and 0′s. Think of something like Morse code at an incredible speed.There are international standards and protocols established to define the structure of those packets, each bit means something different depending of its location in the “package”. The size of the package also differs according to the needs of the network.Many years ago our internet connection was established by a phone line connection, the modem used the phone cable to send and receive these packets of information. My father owned a common one that handled a 14.4Kbps speed rate; this means that the data transfer was 14 thousand bits per second. Fast?Later in 1998 was approved the first standard for ADSL, this new technology enabled faster data transmission over copper wires and used different frequencies from those used by the voice telephone call. Splitters or filters are used to enable the use of the phone line (PSTN) simultaneously with the ADSL service. Latest versions of this technology allow faster rates up to 24Mbps downstream; this means 24 Megabit or 24 million of signals per second.Are these numbers large enough? Another standard that has evolved tremendously in the last years is Ethernet. Though it was commercially introduced in 1980 with a basic 1Mbps speed, now has surpassed the 10G barrier. By 10Gbps, we are talking about 10 Gigabit or Billion of Bits per second. Of course, copper wires cannot withstand such speeds. Even with modern modulation techniques electrical signals are far from being profitable at extraordinarily high rate speeds. That is why another physical wire is used, the Optical Wire.At the very beginning, the ultra high speed rates were used only to connect bulk signals at extraordinarily long distances throughout countries, states and even continents. These days network architectures like FTT-x (Fiber To The X) allows users to take advantage of optical networks in their home and office by the Last Mile services as fast as 1Gbps. Why is fiber optics faster than copper based cables? Simply put, optical wires are not filled with electrical signals, but light. How fast can light be? This is when real enormous numbers would enter the picture.An optical fiber is a flexible, transparent fiber made of glass or plastic and slightly thicker than a human hair. It is used as a “pipe”. This “pipe” transmits light from one end to another by reflecting it in the “walls” of the wire. The light is emitted by a finely adjusted laser. This wire is well shielded to prevent the escape of light and favor the internal reflection. Today, the WDM (wavelength-division multiplexing) technology, allows transmitting different wavelengths (channels-colors) in a single optical carrier. To put it in basic words is possible to send many light beams of different colors into the same optical wire. Each one of them carries its own data of 1′s and 0′s.How fast is it? In year 2011, a record was established when tests reached 273Gbit per second in each of the 370 channels; all summed up are 101Tbit, meaning 101 Terabit per second, this equals to 101 trillion bits per second. January 2013 saw a new record reached in a multi-core fiber wire with 1.05Pbit. 1 Peta bit equals to 1,000,000,000,000,000 bits, one quadrillion bits per second. This means that we could transfer as much information as 2328 double-layer Blu-Ray discs each second.The numbers are astronomical, and also the cost. Services provided directly through Fiber Optics are expensive at the moment. Later on as technology keeps evolving these insane speeds will become cheaper, right now some Fiber To The Home services of 100Mbps are not that expensive though they are not available everywhere.We can finally say that we achieved warp speed in data transfer. Will we find the limit of fiber optics capacity? How will this keep growing? Only time will tell.