The Science Behind Cable And Fiber-Optic Connections

By June 14, 2019The Latest
The Science Behind Cable And Fiber-Optic Connections

To connect to the internet, the vast majority of today’s users have a DSL, cable, or fiber connection.  Each one uses different technology to bring information and downloads into your home or business.  There’s a lot of design and infrastructure involved in making these connections, but the biggest differences between them comes from the cable’s design.


A DSL or digital subscriber line is a way to transmit digital information over a telephone line.  A digital transmission can send more information than the old analog signals, but they still use the same wires that connect to just about every home in America.  They do this by sending an electric signal that quickly changes frequencies to mark every one and zero.  With a fast enough modem, this signal can offer gigabit internet speeds.  However, telephone wires use unshielded copper to reach a home, which means the transmission can be disrupted by a strong radio signal nearby.


“Cable” specifically refers to coaxial cables.  These cables consist of a copper core, some flexible insulation, a woven copper shield, and then the outer layer of insulation.  The two copper layers are the “co-axis” that give the cable its name.  The woven copper doesn’t transmit information:  instead, it absorbs radio interference so that the core can send a clear and protected signal.  Telephone companies use coaxial cables to connect cities together, and cable companies use them to send stronger and more reliable signals to people’s homes.  However, they aren’t completely immune to interference.

Fiber Optic Lines

Fiber-optic cables don’t transmit electricity or radio signals.  Instead, they use light frequencies by flashing lights at either end of special glass or plastic tubes that can carry that light signal no matter how much it twists or bends.  As fast as electricity is, light is even faster, and that’s why fiber connections at home start at hundreds of megabits or gigabit internet speeds.  They also don’t have to worry about radio interference or someone hijacking the cable connection since they don’t use radio transmissions.  However, fiber-optic cables are more expensive to create and easier to break.

Fiber-optic cables have been the backbone of internet communication for years, but they’re only now reaching homes, businesses, and other end users thanks to the cost of making them and laying new cables.  Still, if you live in an area with a direct fiber connection, you should take advantage of it.  While the electric cables are reaching their limits, a gigabit internet connection is only the beginning when it comes to fiber-optic cables.