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Range and Coverage Issues
An AP’s functional range (the maximum distance from the access point at which a device on the wireless network can receive a useable signal) and coverage (the breadth of areas in your home where you have an adequate radio signal) are important criteria when selecting an AP. Wi-Fi equipment is designed to have a range of up to 100 meters when used outdoors without any obstructions between the two radios. Coverage depends on the type of antenna used.
Just like it’s hard to know how good a book is until you read it, it’s hard to know how good an AP is until you install it. Buying an AP is definitely the type of thing for which you do your research ahead of time and hope that you make the right choice. Buying ten APs and returning the nine that you don’t want is simply impractical. (Well, maybe not impractical, but rather rude.) The key range and coverage issues, such as power output, antenna gain, or receive sensitivity (which we cover in Chapter 2) aren’t well labeled on retail boxes. Nor are these issues truly comparable among devices, either, because of the same lack of consistent information. Because many of these devices are manufactured by using the same chipsets, performance usually doesn’t vary extensively from one AP to another. However, that is a broad generalization, and some APs do perform badly. Our advice: Read the reviews and be forewarned!
In Chapter 2, we tell you about the differences in range between 802.11b/g systems and 802.11a systems, with the latter having slightly less range, all other things being equal. Of the many good reasons to go for 802.11a systems, a big one is the lack of interference in the 5 GHz frequency range. And if you have range issues, we help you figure out how to boost that range (and your throughput) in Chapter 18.
Manageability
When it comes to installing, setting up, and maintaining your wireless network, you’ll rely a lot on your device’s user interface, so check reviews for this aspect of the product. In the next sections, we discuss the many different ways to control and manage your devices.
Web-based configuration
APs, wireless clients, and other wireless devices from all vendors ship with several utility software programs that help you set up and configure the device. An important selling feature of any wireless device is its setup process. The
98 Part II: Making Plans
ideal setup procedure can be accomplished quickly and efficiently. Most available APs and devices can be configured either through the wired Ethernet port or through a USB port.
The best setup program varieties enable you to configure the device by connecting through the Ethernet port and accessing an embedded set of Web (HyperText Markup Language; HTML) pages. Look for an AP with one of these. This type of setup program — often described as Web-based — can be run from any computer that’s connected to the device’s Ethernet port and that has a Web browser. Whether you’re using Windows, the Mac OS, or Linux, you’ll be able to access any device that uses a Web-based configuration program.
Software programming
When shopping for an AP, look for one with an automated setup process. Several AP manufacturers provide setup software that walks you step by step through the entire process of setting up the AP and connecting to your network. The Windows variety of automated setup programs are typically called wizards. If you’re new to wireless technology, a setup wizard or other variety of automated setup program will help you get up and running with minimum effort.
Versions of Windows starting with Windows XP and versions of the Mac OS starting with Mac OS 9 are more wireless aware than earlier versions of these operating systems. Automated setup programs are typically quick and easy to use when written to run on either Windows XP or Mac OS 9 or later.
Performing firmware updates
Most firmware updates come in the form of a downloadable program that you run on a computer connected to the AP (or other device) by a cable (usually Ethernet but sometimes USB). Make sure that you carefully read and follow the instructions that accompany the downloadable file. Updating the firmware incorrectly can lead to real headaches. Here are a few tips:
Make sure that you make a backup of your current firmware before performing the update.
Never turn off the computer or the AP while the firmware update is in progress.
If something does go wrong, look through the AP documentation for instructions on how to reset the modem back to its factory settings.
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Even if an AP comes with a setup wizard, it will also ship with configuration software that permits you to manually configure all the available AP settings. For maximum flexibility, this configuration software should be Web based (see the preceding section).
Telnetting to your device
When all else fails, you can rely on some good old, stand-by backdoors in computing. With your computer, it’s the command prompt interface. With your wireless device, it’s telnetting, which sounds very Scandinavian but isn’t even close. Telnet is a terminal emulation program for TCP/IP networks such as the Internet; a terminal emulation program emulates what you would see if you were sitting at a terminal attached to the device that you want to manage. The Telnet program runs on your computer and links your PC to a device on the network: in this case, your AP. You can then enter commands through the Telnet program, and they will be executed as if you were entering them directly into the AP or through the manufacturer’s Web-based program.
To start a Telnet session, you enter the IP address of the device and log in by entering a valid username and password. You will then be presented with a screen that is decidedly old-fashioned, but you can get the job done here. In order to telnet to a device, you might have to connect with it via a serial interface cable or a null modem cable like a cross-over Ethernet cable (an Ethernet cable with certain wires reversed). Danny recently had to use Telnet to manage a dialup router that he had just purchased on eBay because the software provided with the router wouldn’t support XP . . . but he could get in via telnetting.
Windows ships with a free Telnet program: HyperTerminal. If you find that your software won’t work and you need to get to the device, ask Technical Support whether you can telnet to the device (and leave the skis at home).
Upgradeable firmware
Wireless networking technology is still evolving. As a result, many features of Wi-Fi access points are implemented in updateable chips known as firmware. Before you decide which AP to buy, determine whether you’ll be able to get feature updates and fixes from the vendor and whether you can perform the updates by upgrading the firmware (see the nearby sidebar “Performing firmware updates” for some pointers). Check also for updated management software to match up with the new or improved features included in the updated firmware.