May 2003

When choosing a networking design for home or office, at this point in time there are two basic alternatives: Hard-wired Category5 (Cat5) wiring or wireless (aka Wi-FI) 802.11a, 802.11b or the newest 802.11g systems. The two choices offer trade-offs as with all decisions in life. The wired option means the greatest speed and reliability. 100BaseT Cat5 wiring will give you speeds up to ten times the speed of wireless, but you may find it impossible or unsightly to retrofit some buildings with Cat5 wiring. Wireless, on the other hand. Requires no wiring - and is therefore easier to implement. You may find, however, wireless pitfalls you were unaware of.

How about speed? 100BaseT Cat5 wiring, while theoretically capable of 100 Megabits per second (Mbps), typically provides around 25Mbps sustained data transfer. 802.11a and 802.11b, rated at 11Mbps, typically yield 1-4Mbps (sometimes more). The new 802.11g systems (rated at 54Mbps) are, of course, faster than their predecessors, but still considerably slower that Cat5. The speed factor loses importance if you are only sharing Internet access, as even T1 Internet access is only half the speed of a typical wireless network. If you intend to share files and printers over your network, wireless may be too slow for your needs.

The current crop of wireless networking products operates in the 2.4GHz frequency range. As a result, they are compromised by 2.4GHz cordless phones and numerous other environmental conditions. Several manufacturers, including SMC and Linksys have recently announced a 5GHz system, which circumvents the problem of interference by cordless phones. Dual-band (2.4 and 5HGz) components are available that may be a solution for those who need compatibility with legacy 2.4GHz Wi-Fi installations.

Things to consider when selecting and installing wireless network components:

1: Antenna Style… Internet Gateways and Routers with external antennae are more reliable than the units that have internal antennae. NICs (Internal and USB) also work better with external antennae, as the wave propagation is superior and the signal has a chance to escape the metal chassis of the computer. The USB interface seems to work the best overall, as it can be placed some distance (2 - 6 feet) from the computer itself, improving wave propagation and allowing you to adjust the location until you have optimum performance.

2: Objects That Interfere With Wireless Signals…
Large-screen TVs will interfere with the signal if they are near the line-of-sight path between the gateway and the remote computer.
Large masses of metal such as AC ductwork, fireplaces, vents and fire-floors will deplete the wireless signal.
Brick walls, likewise interfere with wireless wave propagation.
Cell phones and microwave ovens, when in use, can damage the integrity of the wireless signal.

3: Multiple Access Points… Some higher-end systems support 'repeaters' or multiple Access Points. By distributing two or three of these throughout your home or office you can get around the signal strength problems that may be caused by either distance or loss due to objects described under item 2 above. Multiple Access Points will not, however solve interference problems caused by 2.4GHz cordless phones.

4: The Cost Factor is pretty much 'a wash', as wireless costs more for the hardware, but less to install. Category5 wiring is time-consuming to install, but the materials are inexpensive.

5: Security… Anyone near you (neighbors or someone in a passing car) can access your home network if you use a wireless network without encryption. Don't think it can't happen to you. Just as there are people who write viruses, 'key' cars and TP houses, there are individuals with nothing better to do than cruise neighborhoods with a wireless network card and a laptop computer looking for something to vandalize.

Remember… "Your mileage may vary." Every wireless installation is different. With exactly the same set of components in a different building, entirely different results may occur. Your installation may work perfectly one day and disconnect everyone the next - or randomly disconnect only one or more users. There are no guarantees that any consultant can make regarding wireless networking, as there are too many variables to consider - and the end-user can do things that negatively impact wireless performance.

For instance:
Moving a Wireless Access Point or USB NIC only a few inches may render the system non-functional in some installations.
Adding a cordless phone - or using one in close proximity to a wireless computer or Access Point can knock all computers off-line.
Power glitches can lock up the Wireless Access Point on some models and require a reset before wireless operation is restored.

Wireless networking is incredibly convenient - especially if you use a laptop in your home and need it connected to the rest of the world. But will it work? We have installations that work flawlessly. And we have some that are a 'moving target', where it works most of the time, but has to be 'rebooted' periodically to stabilize. In many situations, the best approach is a combination wired / wireless system. Cat5 wiring is employed where convenient and wireless is added to accommodate those areas or computers where wiring is impractical.

As you can see, wireless networking may or may not be your best choice. Wi-Fi may work great in one location and may not even be feasible in another. My recommendation: Do your research beforehand, consult with a professional, knock on wood, rub your rabbit's foot and keep your fingers crossed.

Warren Harris owns and operates The Computer Wizard in Plano