Networking without Wires
The allure of wireless networking is two fold. Once wireless, as an end-user you are no longer tethered to a desk. Surf the web, write e-mail or whatever from wherever you happen to be in the house - bed, bath, the sofa, whatever - it's far more social. The second great attraction is the lack of wires - it reduces the number of cat5 cables that have to be run, and there are fewer cables traipsed across the floor to trip over.
802.11b
802.11b offers a nominal 11MBps network connection under perfect conditions with encryption turned off. Although this sounds paltry when compared with your average 100Mbps LAN, bear in mind that this is several times faster than the upstream internet connection in most homes. It is sufficient to stream MP3's over, but doesn't provide enough bandwidth for video streaming in real time.
But does the technology deliver? The answer has to be an emphatic yes. There are a couple of caveats to be aware of, as always, however. The range of the base stations are limited - and certainly less in practice than the manufacturers "best case" figures would have you believe. The performance of the PC card wireless network cards varies drastically - primarily, I think, because of variations in the antenna design. The difference in performance can be measured in terms of tens of feet in some cases, so it may well be worth researching carefully what works best in your environment. Finally, there are security issues that you should at least be aware of, even if you choose to ignore.
The Hardware
Setting up a wireless network for a number of PC's typically requires a wireless base station. This works in much the same way as the base station for a cordless phone - it is plugged into your fixed data network and a power supply, and you are up and running. In addition to the standalone format, wireless access points are also available with integral broadband routers, ISDN routers or analogue modem options if required. You should be aware, even though an access point has a limited range, and can be configured to use a weak form of encryption (WEP), that wireless networking is inherently insecure. If security is important to you, the access point should be placed behind a firewall (e.g. in a DMZ).
Each PC that is to be joined to the wireless network then also needs a Wireless LAN card. These are available in PC card (PCMCIA) format, CF (Compact Flash) format - for use with iPaq PDA's for example, PCI/ISA format for installation inside a PC, or USB dongle format for external connection to a PC. The range achieved with wireless LAN cards depends primarily on good aerial design - not all cards are alike! I have had excellent results with Lucas/Agilent Orinnoco cards, and very mediocre performance from Compaq WLAN 100 cards. Installation of the cards should be a simple matter plug-and-play. Life will be simpler if you use the same vendors products for the access point and PC cards, especially if you use encryption. The WLAN standard does not include the way in which the WEP encryption key is specified, so interoperability of products with WEP turned on cannot be guaranteed, although it is usually ok provided the drivers allow the key to be entered manually in hex, rather than generated from a pass phrase.
For smaller wireless networks, it is possible configure PC cards to operate in peer-to-peer mode, allowing them operate without the need for a base station. Depending on the operating systems used, it may also be possible for a peer-to-peer node to act as a router to a wired network (although this PC will obviously need to be powered up continuously to provide access to its peers).
If you have a requirement for short range peer-to-peer networking, this can also be achieved using bluetooth dongles - slower, with a short range, but very cheap.
For devices that cannot accept a wireless network card, two options are available. Some manufacturers access points can be configured as a bridge - allowing a second access point to act as a wired network point to a remote device. Alternatively, PC card carriers are available which provide accept a wireless LAN card and provide a standard ethernet socket for the connection of a single wired device. Both options are, unfortunately, costly.
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