Technical Constraints Still Hamper the Internet
For years, the Internet’s technical constraints went hand-in-hand with the realities of Internet usage. At first, most people viewed Web pages but did little to create or change them. Web journals, photo sites and video sharing didn’t come until later. Even when users had a need to send information — an e-mail here, a shopping transaction there — the amount of data was small.
High-speed Internet services that offered relatively slow speeds for sending, or uploading, data served most consumers fine.
But as those consumers evolve into contributors and require better upload speeds, many of the old technical constraints remain.
Consider DSL services from phone companies.
The souped-up phone lines were originally developed for video on demand. Most of the traffic goes from the service provider to the home. Users only need to send occasional commands to buy and start shows.
So engineers felt justified in designing a system that largely sent traffic in one direction.
In doing so, they were able to limit interference between the two signals — one for each direction — sharing the line, said John Cioffi, a Stanford engineering professor and pioneer in DSL technology. It would have been possible to give both signals equal treatment, he said, but that would have reduced the line’s overall capacity.
Think of it as two people next to each other, both shouting while trying to listen to something from a distant location. “All you can hear is your neighbor,” Cioffi said.
“If your neighbor is only allowed to shout very infrequently, then most of the time you can listen,” he said.
In other words, limit traffic from the home to the central office so that everyone can get good download speeds.
Similar limits exist for cable, though for different technical reasons.
Decades ago, the Federal Communications Commission assigned broadcasters a range of frequencies, starting with 54 megahertz for Channel…
