With ever-increasing needs for bandwidth, the capacity of the cables we use to connect our computers and network devices continues to come under scrutiny. In the past, fiber-optic cable would always beat copper Ethernet cable hands down. However manufacturers have continued to update the technology behind Ethernet, meaning it can be just as fast as some fiber-optic cables today. When comparing the two, it's important to note that while Ethernet cable and fiber-optic cable are completely different, fiber-optic cable can be used in Ethernet networks. Ethernet refers to a collection of protocols and not just the cable. Fiber-optic cables and connections are also called Ethernet when they are designed for this same set of protocols.
Fiber-optic cable is composed of one or more thin strands of glass or plastic, which transmits light from one end to another. CAT5 cable and its variants, the cables traditionally used for Ethernet, is somewhat heavier, composed of copper wires that conduct electrical signals instead of light. Because interference from outside radio and magnetic interference can affect transmissions, the wires inside the protective jacket are twisted along the length of the cable to reduce signal loss. This type of protection is known as unshielded twisted pairs (UTP). Fiber-optic cables are often bundled together and wrapped within a protective casing, so although the individual strands are smaller than Ethernet cable, the entire bundle can often be thicker.
Speed and Range
At distances up to 1.86 miles, single-mode fiber-optic cable can transmit data up to 10 Gbps, but it is used primarily for video. It is used primarily for high-bandwidth video or as a backbone to connect networks between buildings. Multimode fiber, which is used for voice, data, and video, has a data rate up to 1 Gigabit per second for distances under 1.24 miles. Ethernet data rates vary depending on the cable used. The newest, 10 Gigabit Ethernet, transmits up to 10 Gbps. Gigabit Ethernet transmits up to 1 Gbps. Fast Ethernet, still the most common cable used in homes and offices today, transmits up to 100 Mbps (approximately 0.1 Gbps). The oldest version, Ethernet, transmits up to 10 Mbps, but is difficult to find today. Ethernet has a range of only 328 feet. This short range is the reason the protocol is limited to home and office local-area networks.
When it comes to computer networks, terminating Ethernet cable is almost always easier and faster than terminating fiber-optic cable. Ethernet cables can be connected to any RJ-45 connection found on most desktop computers, routers and modems. Very few desktop computers come with fiber-optic adapters, however you can get these adapters to connect yourself. The most common fiber-optic connector is the Gigabit Interface Converter, which can be installed on most desktop computers, provided you have another computer or device with its own GBIC adapter. It should be noted that fiber-optic cable is also used on other electronics, including audio devices, and isn't limited solely to networks.
When connecting computer networks over short distances, using Ethernet cable is generally less expensive than fiber-optic cable. The cost of the cable itself is a factor. Ethernet uses copper, which is more expensive than the glass or plastic in fiber-optic cable. Fiber-optic connections are more expensive. However, if you need to cover a long distance, the disadvantage of Ethernet is its maximum range. A switch or other network component must be installed every 328 feet, driving up the cost significantly. Consequently, fiber-optic cable is less expensive over long distances.
- SearchNetworking: Definition: Fiber Optic
- Line Provider: Optical Fiber and 10 Gigabit Ethernet
- University of Michigan: Fiber Optic Cable
- Stanford University: CS101 - Introduction to Computing Principles: Computer Networking
- Search Networking: FDDI (Fiber Distributed Data Interface)
- Cisco: Gigabit Interface Converter (GBIC) Module and Small Form-Factor Pluggable (SFP) GBIC Module
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