Why is fiber optic cable faster than copper cable?

The characteristics of fiber optic cables

Fiber optic connections enable data transmission at higher speeds, longer distances, and higher throughput than copper wire. Among the many advantages of fiber optics over copper wire, the most significant is its excellent signal transmission speed. For example, a local area network based on modern copper cables can support 3,000 concurrent calls, while a similar fiber optic system can handle more than 31,000 concurrent calls.

The fundamental difference lies in the transmission medium: copper wires rely on electrical currents for transmission, while optical fibres rely on pulses of light in glass fibres for transmission. Both encode data by interpreting energy fluctuations. However, light in fibres not only travels faster, but also maintains signal strength over long distances. Instead, the electrical pulses of copper wire attenuate, leading to signal loss. This inherent limitation also explains why copper wires are generally considered unsuitable for modern internet networks.

The advantages of fiber optic cables

1. The bandwidth of fiber optic cables is much larger than that of copper cables. Its standard performance can reach up to 10 Gbps, and the speed is expected to be further improved as future standards continue to improve. Actual performance depends on the cable type: single-mode fiber has a transmission distance much greater than 62.5 microns or 50 microns multimode fiber. In contrast, multimode fiber is mainly used for short-range communication (e.g., in buildings or campuses), so it can support data rates of up to 100 Gbps.

2. Fiber optic cables can provide more secure communication due to their inherent anti-eavesdropping, anti-electromagnetic interference, and anti-blocking properties.

3. Fiber optics have low attenuation characteristics, ensuring minimal data loss over long distances because the optical signal does not attenuate significantly during transmission.

4. Fiber optics provide extremely reliable data transmission. Its glass core is non-conductive and not affected by environmental disturbances, unlike copper wires. In addition, fiber optics are less sensitive to temperature fluctuations and can function properly even when immersed in water.

5. The popularity of media converters and the falling cost have made it easier to migrate from copper to fiber optics because it allows for seamless connectivity with legacy systems.

6. Fiber optic cables are not affected by electromagnetic interference and environmental noise, as optical signals do not interfere with each other between cables. This makes them ideal for high voltage or lightning-prone areas. In addition, since they do not carry current, there is no fire hazard.