Wireless Standards Explained and Compared
Thursday, October 23rd, 2008There are numerous wireless standards available today, with each of them having benefits and also some downsides. If you are looking for a new router, please read the following information so you will be up-to-date about anything wireless.
The oldest one, 802.11a, is meant for short distances (upto 50 meters) with maximum theoretical speeds of upto 54mbps. The wireless a standard uses the clean 5.0 Ghz spectrum. It is deployed mostly in office-buildings, where a lot of accesspoints are need to cover a small area, which is the number one downside for this type. The upside is that it can be used for many seperate connections, for example to wirelessly connect all people in a conference room, etc. Since the used frequency is not interfered by microwaves and other Wireless gear such as Bluetooth, the connections tend to be stronger. You will most probably not need this standard, there are very few wireless routers that support it anyways.
802.11b is the next-oldest standard, and is still offered in many routers since the newer g and n standards are backwards compatible to this standard. It is rather slow (max. 11mbps), uses the busy 2.4 Ghz spectrum (same as used by bluetooth, microwaves and more), but it will work for distances of upto 100 meters under the best conditions (such as when you live in a cardbox house…).
802.11g is the faster successor of the b standard and does about the same distance, but with the speed of the a standard (54mbps). This means that consumers usually prefer this over the wireless a or b standards. It is backwards compatible with the wireless b standard (it also uses the 2.4 Ghz spectrum) and can therefor be used in many situations.
Some wireless routers that use the g standard, also offer a special Dual Band option. This means that when you use the router, together with a special adapter for your pc or laptop, it will use 2 (or more) channels for just 1 connection. This can be ideal if you only want to connect a single device (your pc) by means of wireless. Do keep in mind that there are only 3 non-interfering channels in the 2.4 Ghz spectrum. Therefor there is not much use in getting Dual Band if you need to support numerous wireless clients. By using 2 bands instead of 1, it not only gets (almost) twice the speed, but might also significally increase the distance over which you can make and keep a connection. It depends on the manufacturer and model
802.11n Pre-N is the first version of the new wireless n standard. This uses the same spectrum as the wireless b and g standards and is backward compatible to these, but multiple bands can be used by default. A normal band is 20Mhz and by using 2 bands this router thus gets near double speeds. Since it still uses the 2.4 Ghz spectrum, it can easily suffer from interference and the reach is about the same as with the wireless g standard. Maximum theoretical speeds go upto about 200 to 270 mbps. Routers made in or before 2006 usually have this form of the wireless n standard.
802.11n Draft is an improved version of the wireless n standard. The differences with Pre-N are minimal, but backwards compatibility can not be guaranteed. Although there have not been any wireless routers on the market that use the 5.0 Ghz spectrum, it does incorporate the possibility for using it. Routers made in or before 2007 usually have this form of the wireless n standard.
802.11n Draft 2.0 is the newest version of the wireless n standard. This does not mean it’s the last version though. Most probably there will be a draft 3.0 version before the wireless n standard is fully developed and ractified by the IEEE at the end of 2009 (hopefully).
Recently, some wireless n draft 2.0 routers have been seen on the market that work on the 5.0Ghz spectrum, while still offering backward compatibility to work on the 2.4 Ghz spectrum with the wireless draft-n, b and g standards. This is a very nice feature since it greatly extends the wireless reach and influence from noise and interference on the 2.4 Ghz spectrum. Since it uses the newest techniques for altering between frequencies, and allows dual-band operation, it can reach speeds of upto 300 mbps to multiple clients if it is outfitted with sufficient antenna’s and internal hardware.
Do pay attention though, since there are only very few wireless n draft 2.0 5.0 Ghz-adapters available for your pc or laptop. Don’t waste all your cash on a new 802.11n draft 2.0 5.0 Ghz Router (what a mouthful), only to find out your pc or laptop will only be able to connect to older types (might work, but not at max speed) At the time of writing the Draft 2.0 Adapters are not even available for purchase, whilst the Routers are!
