In my last tutorial, I discussed the applications and benefits of installing a wireless local area network in a home office or a small office. If you have multiple computers or want the flexibility of using the network from anywhere within the house, then you need a WLAN (define).
Let's now take a look at the ins and outs of installing a Wi-Fi network in a home office or a small office.
Choose a Flavor of Wi-Fi
In order to ensure interoperability, focus on using Wi-Fi certified products (define). Your choice is 802.11b/g (2.4GHz), 802.11a (5GHz), or dual-band that includes both 802.11b/g and 802.11a.
For most applications, 802.11b/g will suffice. You'll have up to 54Mbps data rates with fairly good capacity. The slower (11Mbps) 802.11b is interoperable with nearly all WLAN enabled devices, and probably considerably cheaper if you can even find them anymore.
The need for 802.11a-only networks is fairly rare, especially within a home office setup. If you plan to make use of special 802.11a applications (there aren't many yet) or just want to position yourself for possible future 802.11a applications, then go with the more expensive dual-band approach. Some companies refer to these products as "tri-mode" because they include all three technologies 802.11a, 802.11b, and 802.11g.
Purchase a Wi-Fi Router
Something to keep in mind is that you need a Wi-Fi router, not an access point. Unlike an access point, a router supplies the necessary network layer functions, such as network address translation (define) and dynamic host configuration protocol (define). This enables multiple devices on the network, such as PCs, laptops, PDAs, and printers, to share the single official IP address (define) that a broadband service provider supplies. If you connect an access point directly to the broadband modem, usually only one device on your network will receive an IP address the access point itself.
To simplify matters, consumer retail stores usually only sell routers. In fact, retail clerks will look at you funny if you ask for an access point.
If you happen to have an access point lying around, you can still make use of it. Simply purchase an inexpensive Ethernet-based router and interconnect it between the access point and the broadband modem. The Ethernet router will then take care of the NAT and DHCP functions.
A single router (or access point) is generally enough to fully cover most homes. For example, a single dual-band 802.11a/b/g router provides full coverage and respectable performance throughout my entire two story house with a finished basement.
Centralize the Router Installation
Install the router within reach of the broadband modem, using Ethernet patch cable. If you haven't already had a broadband connection established, consider having it installed somewhere central to the areas where you'll be using the wireless network. This is typically the center of the home or a small office.
Ideally, install the broadband connection in the same room as any device (such as a printer) that you want to connect to one of the Ethernet ports provided by the router. With two floors, choose installation on the floor where you'll be using the network a higher percentage of the time.
Default Settings Gets Things Going
Default configuration settings on the router will enable users to immediately associate and begin accessing broadband Internet services. Most routers have DHCP already enabled for obtaining the official IP address from the ISP through the broadband modem, and DHCP and NAT are ready on the router to hand out private IP addresses to user devices.
This truly makes the router installation straightforward. Normally, all you have to do is plug in the router and users will readily associate and have access to Internet applications. Be sure, however, to follow vendor-specific installation instructions.
Configure Security Mechanisms
By default, most routers don't have any security enabled, which means that all data packets are sent unencrypted in the clear. A unscrupulous person sitting in a car outside your home or office, for example, can wirelessly monitor these transmissions and see e-mail contents, user names, and passwords. In addition, unauthorized users can access files on computers inside the home and use the Internet through your broadband ISP connection.
If you don't want this to happen, then activate encryption supplied within your router. Wired equivalent privacy (define), WEP for short, is better than nothing, but take advantage of the more advanced Wi-Fi protected access (define) if it is available.
Be Weary of RF Interference
For the most part, RF interference (define) is not a significant problem in homes or even small offices. Microwave ovens and cordless phones, however, propagate RF signals that can cause data frame retransmissions and resulting delays with WLAN users.
For example, a microwave oven in operation can dramatically slow down Web page loads when 802.11b/g users are within ten feet or so from the oven. If this is an issue, try setting the router to channel 1, which generally stays clear of microwave oven interference.
With 2.4GHz cordless phones, the damage goes both ways. When the phone is in use, 802.11b/g users may experience a drop in performance. Also, poor sound quality will likely persist through the phone.
A problem is that there's no optimum channel for the router when trying to minimize cordless phone interference with 802.11b/g WLANs. Ideally, you should use either 900MHz or 5GHz cordless phones.
Jim Geier provides independent consulting services to companies developing and deploying wireless network solutions. He is the author of the book Wireless LANs and offers training focusing on WLANs.
Adapted from Wi-Fi Planet.com.