Learn the Terminology of Wireless Networking

WLAN

A WLAN is a wireless LAN, and a LAN (local area network) is a related group of networked computers situated in close physical proximity to each other. You can find LANs 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.

Wi-Fi

Wi-Fi is an industry name for 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. All mainstream wireless home network gear uses the 802.11 standards today, and the term “Wi-Fi” distinguishes wireless equipment from other network gear.

802.11ac, 802.11b/g/n, and 802.11a

802.11ac, 802.11b/g/n, and 802.11a represent popular wireless communication standards. You can build a wireless network using any of them, but 802.11ax is the newest, fastest, and the way to go.

What are WEP, WPA and Wardriving?

The security of wireless home and small business networks remains a concern for many. Just like using radio or television receivers to tune into station broadcasts, it’s almost as easy to pick up signals from a nearby wireless home network. Credit card transactions on the web may be secure, but imagine your neighbors spying on every email and instant message you send. 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 logged their computers onto unsuspecting people’s home WLANs, essentially stealing free computer resources and internet access. WEP was an essential feature of wireless networks that improved network security. WEP encrypts network traffic mathematically so that other computers can understand it, but humans can’t read it. WEP technology became obsolete some years back, and WPA and other security options have replaced it. WPA protects your WLAN from wardrivers and nosy neighbors, and today, all popular wireless equipment supports it. Because WPA is a feature that you can turn on or off, configure it properly when you set up your network.

Types of Wireless Equipment

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

Wireless network adapters Wireless access points Wireless routers Add-on wireless antennas Wireless signal boosters

Some of this equipment is optional, depending on your home network configuration.

Wireless Network Adapters

Each device you connect to a WLAN must possess a wireless network adapter. Wireless adapters are sometimes 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. Nowadays, though, an increasing number of wireless adapters are not cards but rather small chips embedded inside notebooks 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 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. These are sometimes called base stations. Access points are thin, lightweight boxes with a series of LED lights on the face. Access points join a wireless LAN to a pre-existing, wired Ethernet network. Home networkers typically install an access point when they own a broadband router and plan to add wireless computers to their current setup. You must use either an access point or a wireless router to implement hybrid wired and wireless home networking. Otherwise, you probably don’t need an access point.

Wireless Routers

A wireless router is an access point with other useful functions. Like wired broadband routers, wireless routers support internet connection sharing and include firewall technology for improved network security. Wireless routers closely resemble access points. A key benefit of both wireless routers and access points is scalability. A router’s robust, built-in transceivers can spread a wireless signal throughout a 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 more computers than those without one. If your wireless LAN design includes a router or access point, run all network adapters in infrastructure mode; otherwise, adapters must run in ad-hoc mode. Wireless routers are a good choice when building your first home network. It’s essential to choose the proper hardware when you’re setting up.

Wireless Antennas

Wireless network adapters, access points, and routers use an antenna to receive 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. Still, you can 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 the basic network setup.

Wireless Signal Boosters

Some manufacturers of wireless access points and routers sell signal boosters. A signal booster increases the strength of the base station transmitter. It’s possible to use signal boosters and add-on antennas to improve wireless network transmission and reception simultaneously. Both antennas and signal boosters can be a valuable addition to some home networks after the basics are in place. They can bring out-of-range computers into the WLAN range, and they also improve network performance in some cases.

WLAN Configurations

To maximize your network’s functionality, 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 new network? How many wireless computers do you plan to network, and where will be they be in the home? What operating systems do you or 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?

Install a Wireless Router

One wireless router supports one WLAN. Use a wireless router on your network if:

You’re building your first home network.You want to re-build your home network to be all-wireless.You want to keep your WLAN installation as simple as possible.

Install the 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) get better network speed than computers farther away.

Install 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.You are extending an existing wired Ethernet home network.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 cable the access point to your LAN router, switch, or hub.  You won’t have a firewall to configure, but you still must set a network name and enable WEP on the access point at this stage.

Configure the Wireless Adapters

Configure the adapters after setting up the wireless router or access point (if you have one). Insert the adapters into your computers as explained in the product documentation. Wi-Fi adapters require that you install TCP/IP on the host computer. Manufacturers provide configuration utilities for their adapters. For example, on the Windows operating system, adapters generally have a graphic user interface (GUI) accessible from the Start Menu or taskbar after you install the hardware. The GUI is where you set the network name (SSID) and turn on WEP. You can also set a few other parameters.

Configure 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. 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 see a separate setting for channel number. 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. 

Configure Software Internet Connection Sharing

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 keeps the modem connection and must be on when you use the network. Microsoft Windows offers a feature called Internet Connection Sharing (ICS) that works with ad-hoc WLANs.

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 to 10 feet (about 1 to 3 m) from a microwave oven. Other common wireless interference sources 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 may encounter difficulty maintaining a strong network signal between rooms. Wi-Fi supports a signal range up to 300 feet (about 100 m), but physical barriers reduce this range. Obstructions can affect all 802.11 communications (802.11a and other 5 GHz radios more than 2.4 GHz); keep this in mind when installing devices.

Wireless Routers and 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 create interference. This problem usually happens when both households set conflicting communication channels. When configuring a router (access point), you can (except in a few locales) change the channel number your devices use. For example, in the United States, you may choose any Wi-Fi channel number between 1 and 11. If you encounter interference from neighbors, coordinate channel settings with them. Only using different channel numbers doesn’t always solve the problem. However, if both parties use a different one of the channel numbers 1, 6, or 11, that will guarantee the elimination of cross-network interference.

MAC Address Filtering

Newer wireless routers (access points) support a security feature called Media Access Control (MAC for short) 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 the list. MAC address filtering combined with strong Wi-Fi encryption (ideally WPA2 or better) affords good security protection.

Wireless Adapter Profiles

Many wireless adapters support a feature called profiles that let you 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 and then switch between the two profiles as needed. Set up profiles on any computers you plan to move between your home network and another WLAN; the time you spend now will save time and aggravation later.

Wireless Security

Among the options you’ll see for activating wireless security on home networks, WPA3 is considered the 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 WPA3. Avoid using older WEP technologies when possible, except as a last resort. WEP helps prevent people from casually logging in to 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 devices. You must configure matching security settings on both the router and the client device for the wireless connection to work. Keep your passphrase secret, as others can join your network if 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 the firewall to determine whether you have a firewall configuration problem or some other issue. Turn on and test the wireless adapters one by one to determine if problems are from 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. As you build your network, write down settings like network name, security key or passphrase, MAC addresses, and Wi-Fi channel numbers. Don’t worry about making mistakes. You can alter any of your WLAN settings at any time.

Don’t be surprised if your network’s performance doesn’t match the numbers that the equipment manufacturers list. For example, although 802.11g equipment technically supports 54 Mbps bandwidth, that’s a theoretical maximum that devices may never actually achieve. A significant amount of Wi-Fi network bandwidth goes to the overhead that you cannot control. Expect to see no more than about one-half the maximum bandwidth (about 20 Mbps at most for a 54 Mbps link) on your home network.