IDG Answers is a community of experts who are passionate about technology. Ask a question or answer one below.
Actually, there are many reasons that ISPs and telecom carriers are upgrading networks to fiber. Fiber is much cheaper, costing approximately 5%, pound for pound, compared to copper. For the same volume of copper, fiber can transfer about 1000 times the data. Fiber doesn’t have the same distance limitations whereas copper begins to lose signal strength after 15 miles or so.
One of the biggest benefits simply lies in the design. Fiber uses light, not electrical current. Though relatively low voltage, copper causes some magnetic interference in large trunks. In some industrial sites, copper actually poses a hazard as it can ignite flammable material in certain scenarios. Fiber also transfers data in a different manner than copper which is more efficient.
Copper networks (not all) use a method of passing data along frequencies called time division multiplexing or TDM. In a basic sense, each frequency is only used for a certain amount of time before a signal is passed to another channel. Fiber uses wave division multiplexing (WDM) where a transmission utilizes a single channel throughout the entire process.
And yes, there are adapters that can handle speeds of up to 100 Gb/s. However, service providers can't maintain these speeds to most locations. Such adapters are mostly used on internal networks to pass data between servers, SANs, routers, etc.