Final answer:
Computer data is transported over analog telephone local loops using modulation, with modems converting digital signals into analog. Advanced technologies such as microwave transmission, communications satellites, and optical fibers have significantly improved data transmission quality and speed.
Step-by-step explanation:
The transport of computer data over analog telephone local loops is enabled by a process known as modulation, which converts digital signals into analog signals that can be sent over traditional phone lines. This conversion is necessary because the original local loop infrastructure was designed for voice communications, which are inherently analog in nature. A device called a modem (modulator-demodulator) is used to modulate digital signals from computers into analog signals for transmission over these loops, and then demodulate them back into digital signals at the destination.
Over the years, the methods and technologies for data transmission have evolved. For instance, microwave transmission, communications satellites, and other wireless technologies have greatly expanded the capacity of data networks. The introduction of optical fibers has provided an even better solution for data transmission, with advantages such as low loss, high bandwidth, and reduced crosstalk. These developments have allowed for cheaper, faster, and higher-quality data transmission, ushering in technologies like free Internet-based calling and video calling.