Thursday, July 29, 2004

Fiber Optic Cable


Fiber Optic cables are by far the most advanced cable in the world. They are orange cables with 2 layers of glass inside. The inter layer called the glass core transmits data. The outer layer glass over it reflects data traveling at light speed so it’s trapped going one way. There are 2 glass fibers, one that sends the data to the source and one that receives data from the host. There are two types of fiber called modes. Single Mode Fiber Glass is more expensive, but can transfer up to 2 Gigabits per. second. Multi-mode is a lot cheaper (thing single-mode) and can transmit data at 1 Gigabyte.

Coaxial Cable and RJ-45

We will get to cost later. Right now we want to talk about coaxial cable since this is the primary networked media today. The most common is unshielded twisted pair because it’s the preferred media for Ethernet/LANS. There are 4 classes used today, CAT 4, CAT 5, CAT 5 enhanced and CAT 6. Cat 4 is common with home networks the past 5 years because it’s so cheap. A 10 foot CAT 4 cable will run 10 dollars. A hub will cost 30 dollars, and network cards may cost as little as 20 dollars. However, many people are just getting 802.11b and 802.11g wireless cards for there computers because it’s easier to operate. 802.11b wireless networks transmit at 11 Mbps and 802.11g can transmit at 100 Mbps. 802.11g networks transmit at 120 Mbps. CAT 5 network supplies are now what’s available at Best Buy and CompUSA and the Internet. CAT 3 and CAT 4 networks are now obsolete. Government centers, schools, colleges are already upgraded to CAT 5 enhanced because it covers 1 Gigabyte bandwidth and it’s less costly than CAT 6. CAT 6 is the newest Category in RJ 45 type cable, short for patch cable, its blue or grey. It travels at 1024 Mbit / per second with a 600 MHz frequency surpassing CAT 5e.

Fiber Optic Cable was created when?

Fiber Optic started appearing in 1996, but it was so expensive it was only used in big corporations and universities. Fiber can go longer distances than it did in 1996. Fiber Optic was first used in some houses to bring in sunlight from the roof. It can bend any light source at 90 degree angle. The maximum distance of patch cable is 14 meters. The maximum distance of coaxial cable is 100 meters, and the maximum distance of single mode fiber optic cable is 40,000 meters. Any longer and Fiber glass bandwidth will be affected greatly. A repeater is needed to every 75 feet or so to enhance data pulses. A data pulse is an electronic pulse of computer data, called data packets, when it traveling at light speed through the cable. Today that data pulse can travel from 1 Gigabit to 2 Gigabits at once.

CPU resistance to Fiber Optics Great Bandwidth.

CPU power and RAM will slow data down because data is excepted at the processing rate of the CPU. It’s much like encoding audio, when the cpu is compressing wav to mp3, it is transferring information from the source file to the destination file at the rate of the CPUs own capacity. There is resistance because data going though random access memory and is delayed and waiting in line in the order it is received. This is not noticeable when download is automatically temperately loaded in virtual memory, but when completed, very noticeable when moved to your destination folder.

Seven Advantages of Fiber Optic Cable

1.) It has low Attenuation and high bandwidth. Attenuation is referred to resistance, measured in Ohms, in the wire. Bandwidth is the difference between the highest frequency and lowest frequency of the wire. This is measured in Hz so Gigahertz is 1000 MHz and this means 1 Gigabit of data can transmit at the speed of light. Multimode fiber travels at 1 Gigahertz and Single Mode fiber travels at 100 Gigahertz. Single Mode is obviously faster. Remember Cat 6 patch cable bandwidth is 1 GB running at 600 MHz, the speed of sound.

2.) Low Power Lost – Needs less power to transmit data.

3.) Immunity to electrical interference including lighting and fluorescent light rods.

4.) Smaller weight compared to patch cable. Fiber is 20 pounds per 100 Feet CAT 5 untwisted pair is 50 pounds per 100 feet and coaxial thicknet cable is 200 pounds per 100 feet.

5.) No crosstalk with other fiber cables or unshielded / shielded twister pair cable.

6.) Can’t be tapped from outside line. If someone is taping the line, it must be from a computer terminal connected to a star topology connecting to a fiber wire backbone setup. Fiber is usually used from backbone to backbone cross connects or from building to building. Vampire taps are a thing of the past. No more Mission Impossible tapping.

7.) Fiber Wire can be used from 20 to 50 years before needing to be replaced. It’ll be outdated before it becomes vulnerable to corroding.

What Matter does fiber transmit ?

Fiber is more advanced because it uses protons positively charged particles instead of electrons negatively charged particles. That’s why when you a fry a motherboard because it uses electrons to transmit data. You can not fry fiber optic; only snap it in half if you’re not careful. The orange wire is more fragile than twisted pair.

By Ian March 04, 2004 6:40 PM | revised Nov 07

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