How to Build a Wireless Home Network - Tutorial

Introduction to wireless computer networking

Home Solution & wifi Devices network
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This tutorial will guide you through the process of planning, building, and testing a wireless home network. Although mainstream wireless networking has made amazing strides over the years, wireless technology and terminology remain a bit difficult for most of us to comprehend. This same guide will help small business networkers, too!

Build a Wireless LAN, Step by Step

You can build any typical wireless home network, a wireless LAN (WLAN), using this simple three-step approach:

1. Identify the WLAN design that's best for your situation
2. Choose good wireless gear
3. Install gear and test the configured WLAN

I'll break down each of these steps in more detail.

Ready to Go Wireless?

This article assumes you've already made an informed decision to go wireless rather than build a traditional cabled network. Though prices have dropped dramatically from a few years ago, when wireless gear was quite expensive, wireless networks still aren't for everyone (yet). Unsure that wireless will really meet your needs? Use the following supplementary article to help you choose wisely:

Benefits of Wireless

Wireless offers tangible benefits over traditional wired networking. Ever tried to quickly look up a recipe on the Net while cooking in the kitchen? Do the kids need a networked computer in their bedroom for school projects? Have you dreamed of sending email, instant messaging, or playing games while relaxing on your outdoor patio?

These are just some of the things wireless can do for you:

Next Stop - Terminology

The field of computer networking once sat squarely in the domain of techies. Equipment manufacturers, service providers, and "experts" that study the field of networking tend to go quite heavy on technical jargon.

The wireless networking industry is gradually improving on this legacy, making products more consumer-friendly and easier to integrate into the home. But there is still much work for the industry to do. Let's take a quick look at the common jargon of wireless home networking and what it all means.

When researching wireless equipment to buy, or talking about wireless networking with friends and family, you should have a solid understanding of this basic terminology.

What is a WLAN?

We've already said that a WLAN is a "typical" wireless home network. That's because a WLAN is a wireless LAN, and a LAN is a related group of networked computers situated in close physical proximity to each other. LANs can be found in many homes, schools, and businesses.

Though it's technically possible to have more than one LAN in your home, few do this in practice. In this tutorial, we explain how to build a single standard WLAN for your home.

What is Wi-Fi?

Wi-Fi is an industry name used to market wireless networking products. You'll find a black-and-white Wi-Fi logo or certification emblem on virtually any new wireless equipment you buy. Technically speaking, Wi-Fi signifies conformance to the 802.11 family of wireless communication standards (described below). But because all mainstream wireless home network gear uses the 802.11 standards today, basically the term "Wi-Fi" merely distinguishes wireless equipment from other network gear.

What is 802.11a/802.11b/802.11g?

802.11a, 802.11b, and 802.11g represent three popular wireless communication standards. Wireless networks can be built using any of the three, but 802.11a is less compatible with the others and tends to be a more expensive option implemented only by larger businesses.

Use the supplemental article below to help you pick 802.11 standard(s) for your wireless LAN.

What are WEP, WPA and Wardriving?

The security of wireless home and small business networks remains a concern for many. Just like we use radio or television receivers to tune into station broadcasts, it's almost as easy to pick up signals from a nearby wireless home network.

Sure, credit card transactions on the Web may be secure, but imagine your neighbors spying on every email and instant message you send!

A few years ago, some techies popularized the practice of wardriving to raise awareness of this vulnerability in WLANs. With the help of cheap, home-made equipment, "wardrivers" walked or motored through neighborhoods snooping the wireless network traffic emanating from nearby homes. Some wardrivers even logged their computers onto unsuspecting people's home WLANs, essentially stealing free computer resources and Internet access.

WEP was an important feature of wireless networks designed to improve their security. WEP scrambles (technically speaking, encrypts) network traffic mathematically so that other computers can understand it, but humans cannot read it. WEP technology became obsolete some years back and has been replaced with WPA and other security options. WPA helps protect your WLAN from wardrivers and nosy neighbors, and today, all popular wireless equipment supports it. Because WPA is a feature that can be turned "on" or "off," you'll simply need to ensure it is configured properly when setting up your network.

Next - Types of Wireless Equipment

The five types of equipment found in wireless home networks are:

Some of this equipment is optional depending on your home network configuration. Let's examine each piece in turn.

The building blocks of a wireless LAN are network adapters, access points, wireless routers, add-on wireless antennas and signal boosters. Of these, only network adapters are truly required to build a wireless home network. However, many wireless LANs also utilize some of the other equipment, as explained below.

Wireless Network Adapters

Each device you wish to connect to a WLAN must possess a wireless network adapter. Wireless adapters are sometimes also called NICs, short for Network Interface Cards. Wireless adapters for desktop computers are often small PCI cards or sometimes card-like USB adapters. Wireless adapters for notebook computers resemble a thick credit card ( see Page 1 sidebar for illustration). Nowadays, though, an increasing number of wireless adapters are not cards but rather small chips embedded inside notebook or handheld computers.

Wireless network adapters contain a radio transmitter and receiver (transceiver). Wireless transceivers send and receive messages, translating, formatting, and generally organizing the flow of information between the computer and the network. Determining how many wireless network adapters you need to buy is the first critical step in building your home network. Check the technical specifications of your computers if you're unsure whether they contain built-in wireless adapter chips.

Wireless Access Points

A wireless access point serves as the central WLAN communication station. In fact, they are sometimes called "base stations." Access points are thin, lightweight boxes with a series of LED lights on the face ( see Page 1 sidebar for illustration).

Access points join a wireless LAN to a pre-existing wired Ethernet network.

Home networkers typically install an access point when they already own a broadband router and want to add wireless computers to their current setup. You must use either an access point or a wireless router (described below) to implement "hybrid" wired/wireless home networking. Otherwise, you probably don't need an access point.

Many access point products are available on the market; see the following supplementary article for some good examples:

Wireless Routers

A wireless router is a wireless access point with several other useful functions added. Like wired broadband routers, wireless routers also support Internet connection sharing and include firewall technology for improved network security. Wireless routers closely resemble access points ( see Page 1 sidebar for illustration).

A key benefit of both wireless routers and access points is scalability. Their strong built-in transceivers are designed to spread a wireless signal throughout the home. A home WLAN with a router or access point can better reach corner rooms and backyards, for example, than one without. Likewise, home wireless networks with a router or access point support many more computers than those without one.

As we'll explain in more detail later, if your wireless LAN design includes a router or access point, you must run all network adapters in so-called infrastructure mode; otherwise they must run in ad-hoc mode.

Wireless routers are a good choice for those building their first home network. See the following article for good examples of wireless router products for home networks:

Wireless Antennas

Wireless network adapters, access points, and routers all utilize an antenna to assist in receiving signals on the WLAN. Some wireless antennas, like those on adapters, are internal to the unit. Other antennas, like those on many access points, are externally visible. The normal antennas shipped with wireless products provide sufficient reception in most cases, but you can also usually install an optional, add-on antenna to improve reception. You generally won't know whether you'll need this piece of equipment until after you finish your basic network setup.

Wireless Signal Boosters

Some manufacturers of wireless access points and routers also sell a small piece of equipment called a signal booster. Installed together with a wireless access point or router, a signal booster serves to increase the strength of the base station transmitter. It's possible to use signal boosters and add-on antennas together, to improve both wireless network transmission and reception simultaneously.

Both antennas and signal boosters can be a useful addition to some home networks after the basics are in place. They can bring out-of-range computers back into range of the WLAN, and they can also improve network performance in some cases.

Next - WLAN Configurations

Now that you have a good understanding of the pieces of a wireless LAN, we're ready to set them up according to your needs. Don't worry if you haven't settled on a configuration yet; we will cover all of them.

To maximize benefit from the directions below, have your answers ready for the following questions:

  • do you want to extend your wired home network with a WLAN, or are you building a completely new network?
  • how many wireless computers do you plan to network, and where in the home will be they be located?
  • what operating systems do/will you run on your networked computers?
  • do you need to share your Internet connection among the wireless computers? how else will you use this WLAN? file sharing? network gaming?

    Installing a Wireless Router

    One wireless router supports one WLAN. Use a wireless router on your network if:
    • you are building your first home network, or
    • you want to re-build your home network to be all-wireless, or
    • you want to keep your WLAN installation as simple as possible
    Try to install your wireless router in a central location within the home. The way Wi-Fi networking works, computers closer to the router (generally in the same room or in "line of sight") realize better network speed than computers further away.

    Connect the wireless router to a power outlet and optionally to a source of Internet connectivity. All wireless routers support broadband modems, and some support phone line connections to dial-up Internet service. If you need dial-up support, be sure to purchase a router having an RS-232 serial port. Finally, because wireless routers contain a built-in access point, you're also free to connect a wired router, switch, or hub.

    (See diagram Page 2 sidebar.)

    Next, choose your network name. In Wi-Fi networking, the network name is often called the SSID. Your router and all computers on the WLAN must share the same SSID. Although your router shipped with a default name set by the manufacturer, it's best to change it for security reasons.

    Consult product documentation to find the network name for your particular wireless router, and follow this general advice for setting your SSID.

    Last, follow the router documentation to enable WEP security, turn on firewall features, and set any other recommended parameters.

    Installing a Wireless Access Point

    One wireless access point supports one WLAN. Use a wireless access point on your home network if:
    • you don't need the extra features a wireless router provides AND
    • you are extending an existing wired Ethernet home network, or
    • you have (or plan to have) four or more wireless computers scattered throughout the home
    Install your access point in a central location, if possible. Connect power and a dial-up Internet connection, if desired. Also cable the access point to your LAN router, switch or hub. See the diagram in the Page 3 sidebar for details.

    You won't have a firewall to configure, of course, but you still must set a network name and enable WEP on your access point at this stage.

    Configuring the Wireless Adapters

    Configure your adapters after setting up the wireless router or access point (if you have one). Insert the adapters into your computers as explained in your product documentation. Wi-Fi adapters require TCP/IP be installed on the host computer.

    Manufacturers each provide configuration utilities for their adapters. On the Windows operating system, for example, adapters generally have their own graphic user interface (GUI) accessible from the Start Menu or taskbar after the hardware is installed. Here's where you set the network name (SSID) and turn on WEP. You can also set a few other parameters as described in the next section. Remember, all of your wireless adapters must use the same parameter settings for your WLAN to function properly.

    Configuring an Ad-Hoc Home WLAN

    Every Wi-Fi adapter requires you to choose between infrastructure mode (called "access point" mode in some configuration tools) and ad-hoc wireless ("peer to peer") mode. When using a wireless access point or router, set every wireless adapter for infrastructure mode. In this mode, wireless adapters automatically detect and set their WLAN channel number to match the access point (router).

    Alternatively, set all wireless adapters to use ad hoc mode. When you enable this mode, you'll see a separate setting for channel number. All adapters on your ad hoc wireless LAN need matching channel numbers.

    Ad-hoc home WLAN configurations work fine in homes with only a few computers situated fairly close to each other. You can also use this configuration as a fallback option if your access point or router breaks:

    Configuring Software Internet Connection Sharing

    As shown in the diagram, you can share an Internet connection across an ad hoc wireless network. To do this, designate one of your computers as the host (effectively a substitute for a router). That computer will keep the modem connection and must obviously be powered on whenever the network is in use. Microsoft Windows offers a feature called Internet Connection Sharing (ICS) that works with ad hoc WLANs.

    Next > WLAN Tips and Tricks

    Now let's cover some of the finer points you need to know about home wireless networks.

    Wireless Signal Interference within the Home

    When installing a Wi-Fi router (or access point), beware of signal interference from other home appliances. In particular, do not install the unit within 3-10 feet (about 1-3 m) from a microwave oven. Other common sources of wireless interference are 2.4 GHz cordless phones, baby monitors, garage door openers, and some home automation devices.

    If you live in a home with brick or plaster walls, or one with metal framing, you're may encounter difficulty maintaining a strong network signal between rooms.

    Wi-Fi is designed to support signal range up to 300 feet (about 100 m), but physical barriers reduce this range substantially. All 802.11 communications (802.11a and other 5 GHz radios more than 2.4 GHz) are affected by obstructions; keep this in mind when installing your devices.

    Wireless Routers / Access Point Interference from Outside

    In densely populated areas, it's not uncommon for wireless signals from one person's home network to penetrate a neighboring home and interfere with their network. This happens when both households set conflicting communication channels. Fortunately, when configuring a router (access point), you can (except in a few locales) change the channel number employed.

    In the United States, for example, you may choose any Wi-Fi channel number between 1 and 11. If you encounter interference from neighbors, you should coordinate channel settings with them.

    Simply using different channel numbers won't always solve the problem. However, if both parties use a different one of the channel numbers 1, 6 or 11, that will guarantee elimination of cross-network interference.

    MAC Address Filtering

    Newer wireless routers (access points) support a handy security feature called MAC address filtering. This feature allows you to register wireless adapters with your router (access point) and force the unit to reject communications from any wireless device that isn't on your list. MAC address filtering combined with strong Wi-Fi encryption (ideally WPA2 or better) affords very good security protection.

    Wireless Adapter Profiles

    Many wireless adapters support a feature called profiles that allows you to set up and save multiple WLAN configurations. For example, you can create an ad hoc configuration for your home WLAN and an infrastructure mode configuration for your office, then switch between the two profiles as needed. I recommend setting up profiles on any computers you plan to move between your home network and some other WLAN; the time you spend now will save much more time and aggravation later.

    Wireless Security

    Among the options you'll see for activating wireless security on home networks, WPA2 is considered best. Some gear might not support this higher level of protection, though. Ordinary WPA works well on most networks and is a suitable fallback alternative to WPA2. Try to avoid using older WEP technologies whenever possible except as a last resort.

    WEP helps prevent casual people from logging into your network but offers minimal protection against attackers.

    To set up wireless security, choose a method and assign a long code number called a key or passphrase to the router and all of your devices. Matching security settings must be configured on both the router and the client device for the wireless connection to work. Keep your passphrase secret, as others can easily join your network once they know the code.

    General Tips

    If you've finished installing the components, but your home network isn't functioning correctly, troubleshoot methodically:

    • Can't reach the Internet? Temporarily turn off your firewall to determine whether you have a firewall configuration problem, or some other issue. More - Can't Connect to the Internet?
    • Likewise, turn on and test your wireless adapters one by one, to determine if problems are isolated to a single computer or common to all.
    • Try an ad hoc wireless configuration if infrastructure mode networking isn't functional, and perhaps you'll identify a problem with your access point or router
    • To help you work methodically, as you build your network, write down on paper the key settings like network name, security key or passphrase, MAC addresses, and Wi-Fi channel numbers (then eat the evidence afterward!).
    • Don't worry about making mistakes; you can go back and alter any of your WLAN settings any time

    Finally, don't be surprised if your network's performance doesn't match numbers quoted by equipment manufacturers. For example, although 802.11g equipment technically supports 54 Mbps bandwidth, that is a theoretical maximum never achieved in practice. A significant amount of Wi-Fi network bandwidth is consumed by overhead that you cannot control. Expect to see more than about one-half the maximum bandwidth (about 20 Mbps at most for a 54 Mbps link) on your home network.

    Conclusion

    Armed with the information contained in this tutorial, you're now well on your way to building a working home WLAN. Welcome to the world of wireless networking!

    Next > More About Wireless Networking