In computer networking, which transmission medium typically provides the slowest data rate among common choices (twisted-pair wire, coaxial cable, fiber-optic cable, and microwave links)?

Introduction:
In data communications and computer networking, different physical media support very different bandwidths and noise characteristics. This question tests your understanding of how common media—twisted-pair wire, coaxial cable, fiber-optic cable, and microwave links—compare in terms of typical (not theoretical peak) throughput and the factors that limit their speed.

Given Data / Assumptions:

• We compare widely deployed, standard-quality implementations of each medium under practical conditions.
• Focus is on typical sustained data rates achievable in enterprise/ISP deployments, not absolute laboratory records.
• No special shielding or exotic variants are assumed beyond what is commonplace.

Concept / Approach:

Transmission speed depends on bandwidth, attenuation, noise immunity, and how well the medium supports high-frequency signaling. The more the medium resists interference and preserves signal integrity over distance, the higher the feasible data rate. Fiber-optic media carry light, are immune to electromagnetic interference, and support extremely high bandwidth. Microwave links use high-frequency radio and can achieve high rates given line-of-sight and proper engineering. Coaxial cable has better shielding than simple twisted-pair and thus higher usable bandwidth. Unshielded twisted-pair (UTP), especially older categories, is the most susceptible to noise and crosstalk and therefore offers the lowest typical capacity among the listed choices.

Step-by-Step Solution:

Verification / Alternative check:

Check practical deployments: enterprise backbone links use fiber, ISP last-mile over coax can exceed 1 Gbps, and microwave backhaul commonly carries hundreds of Mbps. In contrast, twisted-pair links are often limited by category, distance, and noise, confirming it as the slowest among the options.

Why Other Options Are Wrong:

Fiber-optic cable: Very high bandwidth and EMI immunity; typically the fastest option.
Microwave links: Can deliver high rates with line-of-sight engineering; not the slowest.
Coaxial cable: Better shielding than twisted-pair; supports higher practical data rates.
Infrared links: Not among the listed core wired/wireless backbones in this comparison and, in many uses, either short-range or specialized; included as a distractor.

Common Pitfalls:

Confusing “modern Ethernet over Cat6/Cat6a” with all twisted-pair; while newer categories are fast, the question compares broad, common media classes historically and practically. Also, do not assume wireless is always slower; modern microwave backhaul can be very fast.

Final Answer:

Twisted-pair wire