Wi-Fi Basics: A Beginner's Guide to the Wireless Web

Maximum PC Staff

Mind your Bs, Ns, and Gs as we break down the ABCs (and many Ws) of Wi-Fi

The popularity of home networks has increased dramatically over the last decade, a phenomenon which can be directly attributed to the increase in broadband availability, but credit is also due to the accessibility that Wi-Fi provides to consumers. Not only are Wi-Fi products easy to configure and relatively inexpensive to implement, but many home computing devices have wireless radios pre-installed.

While connecting to a wireless network can be as simple as a few button presses or taps, there is a lot that goes into making the bits magically travel through the ether. We’re going to take a look at some of the building blocks that go into making your wireless network stable and fast, with an eye toward security and standards. We’ll also cover some of the devices that can improve your wireless network and ways you can use your Wi-Fi while away from home.

Important Terms

In order to have an intelligent conversation about Wi-Fi, there are a couple of key terms that need to be defined up front. The first is the SSID (Service Set Identifier) or network name. The SSID is the door to connecting to a Wi-Fi network, and is often the only piece of information you will need to get connected.

More of a concept than a term is the idea of channels. Like any Radio Frequency based technology, Wi-Fi uses radio waves of different band-widths to transmit data. Channels define the range of wave-lengths that a transmitter uses. For example several of the Wi-Fi standards use the 2.4GHz frequency, which ranges from 2.4000-2.4835GHz. This frequency range is divided into 13 channels which includes substantial overlap. To make matters more confusing only certain channels are usable from a legal standpoint in different countries. The United States for example uses channels 1-11.

802.11 Standards

The term Wi-Fi refers specifically to the IEEE 802.11 set of standards for wireless networks. Different individual standards are designated by a letter following the 802.11, such as in 802.11g or 802.11n. In general all of the 802.11 standards operate on either a 2.4GHz or 5GHz radio frequency, though some can work on both bands.

802.11a and 802.11b are some of the oldest the Wi-Fi standards and operate on the 5GHz and 2.4GHz frequencies respectively. It could be said that 802.11b was the standard that popularized Wi-Fi, and many legacy devices still utilize this standard today. The biggest differentiators between these original standards from a practical standpoint are speed and range. 802.11a enables speeds of up to 54Mbit/s but the shorter wavelength isn’t as effective at penetrating walls and other obstructions making it less feasible for home networks. 802.11b is limited to 11Mbit/s of throughput, but the 2.4GHz frequency handles signal degradation better.

802.11g combined the benefits of its predecessors, offering 54Mbit/s using a 2.4GHz radio. An additional benefit of using 802.11g is the backward compatibility with 802.11b client devices, though using an 802.11b device on an 802.11g network will reduce the data rate for all clients to 11Mbit/s.

802.11n is the current Wi-Fi standard, and supports the use of both 2.4GHz and 5GHz bands. This ability to use both sets of frequencies is known as MIMO (Multiple-Input Multiple-Output). The key benefits to using 802.11n devices are data rates up to 600MBit/s, and some additional security features. 802.11n offers backward compatibility, though for performance reasons these features are optional, and are not always enabled.

Device Types

Much of the confusion with Wi-Fi is due to the number of devices on the market and the range of terms that are used to describe hardware that perform the same functions. The simplest way to look at a wireless network is to realize that there are essentially only two types of devices, Access Points and Clients, both of which can come in a variety of form factors.

An Access Point is generally the core of your wireless network and is generally physically connected to a wired network as well. Configuration of your wireless settings such as the radio channel, security, and SSID is managed on the Access Point itself. Some examples of Access Point type devices are Wireless Routers or Wireless Range Extenders. While the differences between these monikers are subtle, they can be important to how your network is configured. In its purest form, an Access Point is simply a device that connects a wireless network to a wired network. A Wireless Router indicates that the device includes additional functionality from a networking standpoint that will allow various devices to talk to each other and share an internet connection. Range Extenders are a little hard to explain, but essentially combine features of both Access Point and Client to extend the range of your wireless network without requiring you to run additional networking cable.

Wi-Fi Client devices are any device that connects to the wireless network offered up by an Access Point. These could be laptop or desktop computers, tablets, cellular phones, printers, or even home theater equipment. Typically a Wi-Fi client will have some means of connecting to a specific SSID or list of SSID’s, and the ability to configure security settings like an encryption key or passphrase. Clients can also create an ad-hoc or peer-to-peer network, which is made by two clients connecting to each other. This doesn’t offer the same flexibility or power of an Access Point based network, but there are scenarios where a peer-to-peer network makes sense.

Use Cases

Ok, so now that you know the basics let’s get our hands dirty by running through a few common scenarios where you would use a Wi-Fi connection and detail the basic steps to get things working.

The most common example is a basic home wireless network. Let’s say you have two computers, one wired desktop and one wireless laptop. The first device you would need for your wireless network would be an Access Point. For cost reasons it makes a lot of sense to buy one device that will perform multiple roles, so we’ll recommend some sort of wireless router.

Typically a wireless router will offer wired connectivity, so you should connect your desktop in to one of the Ethernet ports. Following the manufacturer’s instructions you will want to enable the wireless interface, configure an SSID, and enable the wireless security features. You will want to make a note of your SSID and security key for later use. The laptop will then need to be configured to use the SSID and security key to communicate to the wireless router.

A second common example is using a public Wi-Fi hotspot, such as a coffee shop or library. This is a much easier scenario as generally there is no security key involved. Simply find the SSID for the Wi-Fi network you wish to connect with and away you go. Be aware that public networks should be treated as such, and using computer security features like antivirus and firewall software is highly recommended. It’s also worth noting that public hotspots also have “terms of agreement” that must be agreed to, and you may want to give those a look before using the connection.

Our third use case is a little more advanced. Let’s pick up where we left off with the home networking example, we have an existing network with a wireless router, but we need to extend the reach of the wireless network into another part of the house. The best solution is to run an Ethernet cable from your wireless router to a location that is central to the area you want Wi-Fi signal. An additional Access Point can be added to the network to provide better signal to a larger area. When adding a second Access Point there are some additional things to consider. You will typically want to configure the same SSID and security key, to allow your wireless devices to roam between Access Points. However, you need to make sure that the Wi-Fi channels are configured differently, and that your frequency use does not overlap. This will help prevent interference which could potentially degrade the usability of your wireless network.

Best Practices

Wi-Fi networking offers great flexibility over wired networks and the speed increases in the latest standards make it a very attractive solution, but there are tradeoffs. The biggest area of concern for people trying to get the most from their wireless network is signal strength. Wi-Fi signals are fairly robust, and will generally function throughout a good sized house, but sometimes there are simple solutions for improving your coverage.

The best rule of thumb for getting the best coverage from your Access Point is to centrally locate it in the area where you want to be able to get a signal. If your house is the primary area of use you should find a location as close to the center of the house as possible. If you want coverage in your back yard you might think about moving the Access Point closer to the rear of the house.

An additional thing to consider is the height at which you place your Access Point. Generally there are more physical obstructions the closer you get to the floor. Small furniture, electronics, even pets or other people have a negative effect on radio frequency. Placing your Access Point on a bookshelf or even mounting it on a wall can increase your signal dramatically. Of course adding variables like a house with multiple floors adds complexity, and your results will vary.

Our last recommendation is harder to troubleshoot, and can be painful to execute. Wi-Fi devices use radio frequencies that are open game for other wireless standards and devices like Bluetooth, cordless phones, or wireless peripherals like a mouse or keyboard. Interference is often caused when two wireless devices are attempting to operate using the same radio frequency. Most Wi-Fi Access Points allow for the user to change the channel used by the radio, which will sometimes help mitigate interference caused by other wireless devices.

Security

We would be remiss if we didn’t point out that Wi-Fi networks need to be secured. There are many reasons for this ranging from protecting your personal information to not getting sued because of what an unauthorized user was doing with your network. The bottom line is security is worth being concerned about.

Wired Equivalent Privacy (WEP) was once the standard for Wi-Fi security, but has been frequently maligned and is not considered secure. Several tools exist that will analyze encrypted Wi-Fi traffic and provide the security key with little technical knowledge required.

Wi-Fi Protected Access (WPA) is a more secure solution than WEP, and is supported on most modern Wi-Fi devices. WPA also has vulnerabilities, but may be your best option if you’re using an older Access Point.

WPA2 is the current standard for Wi-Fi security, and is required for new devices seeking Wi-Fi certification. WPA2 supports backwards compatibility with WPA clients, so there shouldn’t be any client compatibility reasons to revert to WPA.

An additional security step that is commonly used is a hidden SSID. This isn’t a full security measure, but can help prevent unauthorized users from seeing your network.

Our last security recommendation is to change the username and password used to log in to your Access Point itself. This will prevent unauthorized users or even viruses from modifying the configuration of your network.

Conclusion

Wi-Fi networks are pretty well here to stay, so you might as well get familiar with the various ins and outs provided by your current configuration. The convenience and flexibility offered by the standard is unparalleled, and the stability, speed, and security are improving by leaps and bounds. When configuring or troubleshooting your wireless network keep our best practices in mind.

For reviews of specific hardware visit our Networking section under Reviews. Also feel free to post your suggestions or ask your questions in the comment section below.

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