WiFi Networks

The earliest "WiFi" networks used a protocol from the Institute of Electrical and Electronic Engineers (IEEE). The committee responsible for that work named it "Protocol 802.11" back in 1997, but it didn't become popular until 1999, when two newer, enhanced versions were created. These were named "802.11A" and "802.11B".

The "B" variant began to dominate, but as vendors began developing and selling related equipment, they found that consumers were reluctant to buy their devices until they were assured of compatibility across brands. Nobody wanted to buy network equipment without assurance that it would be supported into the future and that it would continue to work as other vendors entered the marketplace. An industry alliance was formed to evaluate and publish compatibility. The group felt that the old protocol names were too complicated, so they chose the nickname "WiFi", and they began to publish lists of equipment that could interoperate.

WiFi Router As technology has advanced, newer versions of the 802.11 protocol family have been published. Today's networks, based on Protocols 802.11g and 802.11n, can exchange information much faster and farther than the originals. The committees responsible for these new protocols made sure that they included provisions for communicating with older equipment by "falling back" to older, slower technologies when they encountered them on the same network. Thus the new 802.11n protocol knows how to slow down and communicate with older 802.11g equipment, and 802.11g equipment knows how, in turn, to slow down and communicate with 802.11b equipment.

Today, the "WiFi" logo enjoys a very good reputation. When present on a piece of network equipment, it indicates that the vendor has paid the WiFi Alliance to test and certify that the equipment works as advertised, and that it can be used with other WiFi equipment from other vendors. As a general rule today, consumers trust that any network equipment advertising "WiFi" compatibility can be purchased, installed, configured, and used with confidence in combination with other WiFi equipment, regardless of the underlying protocol details.

However, today's consumers will find 802.11b, 802.11g, and 802.11n equipment for sale on the same store shelves. Some vendors don't pay for WiFi certification, so the WiFi logo may not be present, even on good equipment that will interoperate according to the standards. Informed consumers can make better purchase decisions if they are aware of these basic protocol details:

802.11a: This older protocol isn't used very much, and there is little guarantee that newer equipment will interoperate with it. It also suffers from limited range (about 50 feet indoors). Some businesses actually LIKE that because it can contribute to privacy and eliminate certain problems related to radio interference, but there is little reason for today's consumers to purchase this equipment.

802.11b: This older, slower, limited-range protocol remains very popular, and it's the only popular wireless protocol that is compatible with virtually everything. Speeds range between 1 and 11 million bits per second, over distances of about 100 feet indoors or 300 feet line-of-site. You won't find very much new network equipment that's advertised as "802.11b" nowadays, but all of the newer items know how to slow down to use it. If you have an old 802.11b laptop computer or network adapter, you'll be able to use it at all public wireless "hotspots" whenever you are within about 100 feet of the hotspot antenna. Although 802.11b speed is too slow for High Definition local video between your TV and adjacent PC, it's fast enough to fully exploit your Internet connection. If you are just surfing the web or exchanging email, you'll be fine with this. Skype telephony, and even YouTube and Hulu video can be acceptable if you don't frustrate easily.

802.11g: This is similar to 802.11b, but it's 4 or 5 times as fast, delivering up to 54 million bits per second over the same distances. This is the dominant WiFi protocol at the time of this writing in 2009, and equipment prices have fallen dramatically. With a carefully located central antenna, a typical 802.11g router can serve the needs of most consumers, reaching even the remote corners of a large American home with performance that can fully exploit your Internet connection. Over short distances (50 feet or so) it can deliver acceptable performance between your TV, network disk drives, and PCs for audio and standard-def video applications. Internet telephony and compressed, Internet-based video services like YouTube and Hulu will probably be fine all throughout your house at standard definition.

802.11n: Scientists have discovered that they can put multiple WiFi transmitters and receivers into a single box, with multiple antennas, and that they can even take advantage of radio "echos" and "reflections" to transmit at higher speeds and over greater distances. 802.11n equipment takes advantage of this technology to achieve speeds up to 10 times as fast as 802.11g, with distances that range up to 300 feet indoors or 600 feet line-of-site.  At the time of this writing in 2009, the WiFi alliance is certifying interoperability of equipment from several vendors, based on a preliminary ("draft") standard document that is pending final approval by the relevant IEEE committees. Equipment prices are considerably higher than older equipment, but because this effort has been so popular, it is likely that future wireless equipment will continue to support that draft standard, and it is generally considered safe and prudent to purchase this equipment as part of a consumer network. With a carefully located central antenna, a typical 802.11n router can serve high-definition video and audio to TVs and PCs all throughout a large American home, and Internet applications can be accessed throughout adjacent yards and buildings at distances of 300 to 500 feet or beyond.
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