I have a need for speed. It is not so glamorous as Tom Cruise in his Top Gun fighter jet, but speed is relative.
My husband, Frank, says that it’s not the need for speed, but the speed you need that’s important. I say you can never go fast enough.
Every weekday morning I wake up our two children and start a “speed it up” litany, “All children need to rise and shine. Roll out of bed and get dressed. Come on down for breakfast. Hop to, hop to!”
I zip around toasting pop tarts and pouring milk over Cocoa Krispies while the children shuffle along at a snail’s pace. By 7:10 AM I have pointed them in the direction of the car and given them a motherly shove from the rear. “We’re going to be late for school,” I threaten.
In the afternoon I drag into the house weary from a day’s work and nearly stumble over my son’s wind jacket. It is lying on the floor beneath the coat pegs while he is in the backyard playing soccer. His coat is on the floor because he was moving too fast to actually hang it on the coat peg when he buzzed by after school.
My older sister’s teenage son moves through the house so quickly she refers to him simply as “The Blur.”
Kids obviously have a speed range, slow pokey on the way to school and “The Blur” on the way to play. Telecommunications also has a speed range called bandwidth.
Bandwidth is the amount of data that can travel across a telecommunications system over time. Bandwidth is measured in bits (as in bits and bytes) per second (bps). The bandwidth is a measure of the speed data can travel.
Most of us still have our computer modems connected to our phone line. Phone lines to the home are mostly copper wire which sends an analog signal. Analog bandwidth is defined by the range between the highest- and lowest-frequency signals.
A modem at your end changes your digital data to an analog signal which is a series of continuous electrical voltage changes. The electrical signal then has to be converted back to a digital signal by another modem at the other end of the copper wire. The conversion from digital to analog signal, the time it takes to change the voltage and the finite range of frequencies that can be transmitted all limit copper wire speed.
Integrated Services Digital Network (ISDN) and Digital Subscriber Line (DSL) services are Internet access services available now that provide higher transmission speeds. They still use copper telephone wire, but have special sending and receiving equipment such that the signal is always a digital signal. The voltage change within the copper wire is either positive or negative to represent each bit (binary digit) of data. This on/off signal is faster and more reliable. There is no conversion from digital to analog and back again.
Telecommunications companies today are busy laying fiber optic cable to increase bandwidth. Fiber optic cables are made of glass fibers that have special optic or light-transmitting properties. Glass as a material has been in use since 2500 B.C. The Romans pulled glass into long fibers, but the modern day spun glass fiber was developed in the 1700’s.
The pure glass fibers of today allow light to pass straight through them. These fibers of pure glass that are as thin as a human hair do not bend the light wave much at all.
In fiber optic cables the pure glass fibers carry a light signal that is generated from a laser. Laser stands for Light Amplification by Stimulated Emission of Radiation. Today laser light sources can produce a single light wavelength. The laser light can be “on” or “off” to represent each bit of data.
Lasers can transmit billions of bits per second. In fiber systems today multiple lasers each transmitting light at a different wavelength can send multiple signals along one fiber strand.
One spool of fiber optic cable can carry as many signals as 200 reels of copper wire. In general fiber transmits data in the range of 5 gigabits per second. (One gigabit equals one billion bits per second.) That is speed. That is bandwidth.
So, speed on the Internet is not just how quickly the signal can travel over the copper wire or fiber optic cable. It is also how many signals can share the transport medium simultaneously.
Each morning I will stay on my bandwagon for bandwidth. To improve bandwidth at home I will suggest simultaneous tooth brushing and hair brushing or shoe-tying and pop tart-chewing in addition to simply moving faster.
In several years when my two finally get to George Washington High School life will really be a blur. The marching band will merge with the wide receivers for true bandwidth on the football field. The cheer will be:
Two bits, four bits, six bits, a byte.
We’re the fastest, we travel by light!
The ball will be snapped and the wide receiver will just appear in the end zone with the ball.
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