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Wireless Networking, Part 1: Capabilities and Hardware

2008-06-10来源:

Wireless networking, Part 1: Capabilities and hardware

These days it isn't uncommon for a Home to have multiple personal computers, and as such, it just makes sense for them to be able to share files, as well as to share one Internet connection. Wired networking is an option, but it is one that may require the installation and management of a great deal of wiring in order to get even a modestly sized home set up. With wireless networking equipment becoming extremely affordable and easy to install, it may be worth considering by those looking to build a Home network, as well as by those looking to expand on an existing wired network.

The first installment in this two-part series of Tech Tips will provide an introduction to the basic capabilities and hardware involved in wireless networking. Once that foundation has been established, we'll take a look at a few setup and security related considerations that should be addressed once the physical installation is complete.

Capabilities

The basic standard that covers wireless networking is the Institute for Electrical and Electronics Engineers' (IEEE) 802.11, which is close kin to the wired Ethernet standard, 802.3. Many people will recognize 802.11 more readily when accompanied by one of three suffixes (a, b, or g), used to specify the exact protocol of wireless networking.

The 802.11a protocol first hit the scene in 2001, and despite a small surge in recent popularity, it is definitely the least common of the three at this time. The signals are transmitted on a 5 GHz radio frequency, while "b" and "g" travel on 2.4 GHz. The higher frequency means that the signal can travel less distance in free space and has a harder time penetrating walls, thus making the practical application of an 802.11a network a bit limited. The maximum transfer rate, however, is roughly 54 Mbps, so it makes up for its limited range with respectable speed.

As mentioned, 802.11b and 802.11g networks operate on a 2.4 GHz radio band, which gives a much greater range as compared to 802.11a. One downside to being on the 2.4 GHz band is that many devices share it, and interference is bound to be an issue. Cordless phones and Bluetooth devices are two of many items that operate at this frequency. The range of these two protocols is about 300 feet in free air, and the difference between the two comes down to speed. 802.11b came first, released back in 1999, and offers speeds up to 11 Mbps. 802.11g first appeared in 2002 and it is a backwards compatible improvement over 802.11b and offers speeds up to 54 Mbps.

On top of these protocols, some manufacturers have improved upon the 802.11g standard and can provide speeds of up to 108 Mbps. This doesn't involve a separate protocol, but just a bit of tweaking in areas like better data compression, more efficient data packet bursting, and by using two radio channels simultaneously. Typically, stock 802.11g equipment is not capable of these speeds, and those interested need to shop for matched components that specify 108 Mbps support. I say "matched components" as this is not a standard protocol and the various manufacturers may take different approaches to achieving these speeds. In order to ensure the best results when trying to achieve these elevated speeds, components from the same manufacturer should be used together. For instance, only Netgear brand network adaptors rated for 108 Mbps data transfer should be used with something like the Netgear WG624 wireless router (http://www.geeks.com/details.asp?invtid=WGT624NAR).

Considering your typical