Jeff Duntemanns Drive-By Wi-Fi Guide

2017-07-07 02:10:07

Which Client Adapter to Choose?

With all of that in mind, let me summarize some of the issues involved in choosing what client adapter to buy. Price is sometimes an issue, but price differences are being squeezed by increased competition and are less and less significant all the time, at least on gear targeted at consumers. Cisco and certain other vendors are still getting premium prices from corporate buyers, but the premium covers features that you're unlikely to need or even be able to use in a home office or small office environment.

It often makes sense to decide what sort of client adapters you want for your network first, and then choose an access point from the same company. You're better off with access points and client adapters from the same manufacturer, all else being equal. Getting all your gear from the same company gives you your best chance at having everything work the first time, and it gives the vendor's technical support people no excuse for shrugging their shoulders and blaming 'outsiders' for network problems. Stronger WEP encryption (128 bits and up) is non-standard, and works best when all gear is from one company.

Certainly, if you want to take advantage of a non-standard extension to the Wi-Fi standard (like Texas Instruments' 802.11b+) you must buy all your gear from the same company, ideally all of the same product line, like D-Link's AirPlus line.

Here are some other thoughts to bring to bear on your decision, sorted by adapter type:

PCMCIA (PC Card) Client Adapters

PRO: They're tucked away inside your laptop or notebook and don't require any additional wires or power supplies.

PRO: They install fairly easily. Generally you install some software from a CD-ROM and then plug the card into an empty slot. Windows Plug and Play takes it from there.

CON: Their antennas are uniformly horrible, having the worst 'reach' by far of any antenna in the Wi-Fi world. Few adapters, furthermore, provide a jack for an external antenna.

CON: Many laptops allow you to 'stack' two Type II PCMCIA cards in a dual slot. The problem here is that Wi-Fi PC cards are notorious for physically obstructing adjacent MCMCIA slots, usually with their antenna bulges. PCMCIA Wi-Fi clients often insist on being in the 'top slot.' If another of your PCMCIA card adapters makes the same demand, you may be out of luck. If you already depend on one PC card in a two-card slot, be very careful which WI-Fi PC card you buy for the other slot. Cisco Aironet is very good in this regard. Most others are not so good.

CON: Some newer PC card adapters are 32-bit Cardbus cards, and may not plug into older, pre-1999 laptops.

CON: High-power adapters like Cisco's 100 mw Aironet 350 attempt to compensate for the lousy bulge antenna, but place a greater burden on your battery, and will reduce battery life. Be aware of the power drain of whatever adapters you buy!

PCI Client Adapters

PRO: PCI adapters are 'out of the way' inside your computer and add nothing to the 'cable clutter' on your work surface. There are no wall wart power supplies to fool with, and nothing to take up additional space on your desk.

PRO: PCI adapters use antennas that are adjustable and work relatively well. Also, their antennas are usually removable, so if you need to use a gain antenna at some point you have that option.

PRO: There are PCI card products that allow you to insert and remove a PCMCIA card client adapter through the card spine, allowing you to share an adapter between a desktop and a laptop computer. (Note that this type of product is usually sold 'empty'-without a client adapter, which you have to buy separately.)

CON: PCI adapters require opening up the computer, sometimes pulling out a subchassis, and often fighting your way past fragile ribbon cable runs that get in the way of easy access to the PCI slot into which you hope to plug the card. If you're not completely comfortable opening up your PC (and have no one close by to do it for you) don't even think of going there!

CON: PCI adapters are inexplicably expensive, perhaps because many of them consist of a PCMCIA card attached to a PCI plug-in circuit board.

USB Client Adapters

PRO: They're cheap. Many are now under $50.

PRO: For ease of installation, nothing beats a USB adapter. Typically, you install a client driver from a CD-ROM, and then plug the device in.

PRO: They're very easy to remove from one computer and plug into another if you ever need to do that.

PRO: Unlike most 'external' devices, they take power from the USB port and don't have a separate power supply.

PRO: They're on the end of a wire, so if you're working on the fringe of your access point's range you can move them around a little to find the best signal. Sometimes getting the adapter up to the top of your cubicle wall is all it takes.

PRO: They're usually pretty small, and don't take up much room on your desk. Some models (like the Linksys WUSB11 V2.0 and later; avoid V1) even provide a Velcro patch so you can literally stick them to a cubicle wall.

CON: USB 1.0 ports are not fast enough to support higher bit rates than 802.11b, so you won't find USB client adapters for 802.11a or 802.11b+. Higher bit rate USB 2.0 adapters may eventually appear, but I haven't seen them yet.

CON: Few have dual antennas or even removable antennas, which you might expect in an external device like this.

CON: They're on the end of a wire, and if you don't need the flexibility of positioning (or a better antenna than a PCMCIA card) the wire may be a nuisance.

Ethernet Client Adapters

PRO: For connecting game consoles to your Wi-Fi network, Ethernet clients are often your only option.

PRO: Some Ethernet client adapters can act as wireless bridges with others of their own kind.

PRO: Many models can simply be plugged in and used, without any drivers or other software to install. (There's still some configuration to be done, but it's easy, and once done, the adapter can then be placed on different computers without reconfiguration.)

PRO: As with USB client adapters, Ethernet clients are on the end of a cable and can be moved around. This ability can be useful if your desk sits in a weak spot or a dead spot. (Mine did!) You can move the client to the top of your cube wall or bookcase to get a better shot at your AP.

CON: They're new and fairly uncommon, and thus are more expensive than most other kinds of client adapter. Most are still above $100.

CON: They require external power, and add another wall wart to your collection.

My Recommendations

I have had excellent luck with both Linksys and D-Link equipment, and recommend both manufacturers because they both offer complete product lines. You can find every type of Wi-Fi access point, gateway, and client adapter in both lines and thus can create a very versatile network and still be completely sure that all devices are compatible with all other devices. The only exception I will grant on this point is for the Orinoco Gold PCMCIA adapter for laptops; see my note on this below. In my own testing, it works very well with Linksys, D-Link, and Cisco gear.

Cisco Aironet gear, while excellent, is often overkill for small offices and home offices. You're paying extra for 'corporate' server-dependent features that you probably can't use even if you wanted to.

All else being equal, I recommend USB adapters for desktop computers. They're cheap, easy, versatile, and don't require that you open up the computer.

For your laptop, Orinoco PCMCIA cards are compelling for two reasons:

They have an external antenna jack. Lacking that, if you find yourself in a dead spot, your laptop network connection is just… dead.

Orinoco Wi-Fi gear filters out 'weak IV' values (see Chapter 13) that compromise security. I know of no other adapters right now that have that very important feature.

Unfortunately, the rest of the Orinoco product line is fairly expensive. It's excellent, but you'll pay 30% to 40% more for it. Also, they do not (as far as I know) offer a USB adapter.

To network an Ethernet-equipped game console, I recommend the Linksys WET-11.