In my Scientific American column this month, I chased down the answers to questions about wi-fi that have plagued mankind from the beginning—at least, the beginning of wireless Internet. Things like "Why do I have four bars but still can't connect?" and "Why do I see a phony hot spot called 'Free Public Wi-Fi' in airports?"
Here's an online special for you: Three more questions—and answers, provided by the people who should know.
Where did the name wi-fi come from?
For this one, I consulted a man who was there at the beginning: Alex Hills, author of Wi-Fi and the Bad Boys of Radio. His answer:
"Way back in 1999 the fledgling wireless industry needed a marketing name for the new products that conformed to the technical specifications called 'IEEE 802.11'. 'IEEE 802.11' didn't have much of a ring to it, and the industry association wanted a catchy name. They came up with wi-fi, and that's what's been used ever since.
"It didn’t hurt that the name rhymes with 'hi-fi,' which was short for 'high fidelity,' a term that, back in the day, referred to high-quality sound systems. Some people even say that wi-fi therefore stands for 'wireless fidelity,' but those who were involved in the industry association's process of selecting a name say it's not really true. They say that the name was always just wi-fi."
Q: Whatever happened to Wi-Max? I thought we were supposed to see citywide wi-fi by this time?
From Glenn Fleishman, tech guru and blogger for The Economist’s "Babbage" blog:
"Wi-Max made sense briefly, during the multiple-year gap between third-generation (3G) and fourth-generation (4G) mobile cellular standards. Wi-Max could make use of otherwise unused spectrum quite efficiently and achieve speeds high above the 3G standards of a few years ago; I remember getting network speeds of eight Mbps [megabits per second] via Wi-Max a few years ago, at a time when AT&T and Verizon Wireless could deliver no more than two Mbps.
"But the Wi-Max companies couldn't raise enough money to build out as fast as was necessary to provide a viable network alternative across the U.S. nor build as densely as needed; meanwhile, time—and worldwide standards—caught up. Sprint, Clearwire and a handful of others pledged to Wi-Max, but no other U.S., European or Asian carrier adopted it. LTE [Long Term Evolution] became the dominant 4G standard around the world; even Sprint and Clearwire intend to move to LTE. Wi-Max was amazing for a brief window, but has been left behind.
"As for citywide wi-fi, Wi-Max turned out to be a poor technology to provide consistent coverage. It was cheaper to build fast cellular networks."
Q: What are wi-fi 802.11a, 801.11n and all that? Was there ever such thing as 802.11c, 802.11m and so on?
I went straight to the source for this one: Kelly Davis-Felner, marketing director of the Wi-Fi Alliance—the consortium of engineers who dreamed up (and continues to enhance) wi-fi:
"The 802.11 alphabet soup is a naming system for various projects in IEEE [the Institute of Electrical and Electronics Engineers, the standards organization that defines the technology underlying wi-fi]. The wi-fi industry used to refer to a few of these names to help users know when there had been another performance improvement to the technology, and to navigate the two frequencies in which wi-fi works.
"Here's the timeline:
802.11b: First widely commercialized version of wi-fi, ratified in 2000. Data rate of about 11 Mbps, on the 2.4 GHz [gigahertz] band
802.11a: Ratified in 2002. Operates in five GHz band [where it encounters less interference with cell phones and microwaves] and delivers data rate of about 54 Mbps
802.11g: Ratified in 2003. Fifty-four Mbps in 2.4 GHz band, so backward-compatible with 11b
802.11n: Ratified in 2009. Up to 600 Mbps [in most commercial configurations, about 250 Mbps] in both 2.4 and five GHz frequency bands. A dual-band product that works with 802.11a and 802.11b/g products
802.11ac: Coming to a wi-fi-certified device near you in early 2013. About 1.3 Gbps of data [yes, that's gigabits per second].
"While the Wi-Fi Alliance and the wi-fi industry used to point to these naming conventions a lot, now we just call it wi-fi.
"There are many other 802.11 designations. They refer to a wide array of features that ship in products today—but, thankfully, the industry hasn't burdened users with their names and details.
"Some examples include 802.11i, which underpins the wi-fi security we have today; 802.11e, which includes important mechanisms to support multimedia applications; and 802.11u, which makes up part of the forthcoming Wi-Fi CERTIFIED Passpoint program we are developing, which will make getting on to hot spot networks as seamless as it is with a mobile phone on 3G today."