Wireless Home Networking - Index of

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Part IV: Using a Wireless Network
people have more than one), and over 80 percent of the world’s population
lives in an area covered by cell phone systems. These are big, big numbers.
Now you may be wondering what all of this has to do with wireless networks
(of course, you could argue that even an old-fashioned cordless phone
system is a wireless network, but we’re mainly talking about computer-based
networks in this book). Well the answer is this: These technological trends
are bringing about a convergence of digital (and VoIP) phone technologies
and wireless technologies and are turning your phones (both in-home phones
and mobile phones) into full-fledged members of your home wireless
network.
In this chapter, we talk about what VoIP is all about, including a discussion of
some of the biggest providers of VoIP service. We then talk about wireless
(mainly Wi-Fi) phones that can let you use your wireless network to make
VoIP calls. Finally, we talk about how cell phones are beginning to join into
the Wi-Fi fun, allowing you to use your Wi-Fi network to get better coverage
inside your home while saving money on calls. It’s going to be fun, so read on!
Understanding VoIP
Voice over IP (VoIP) is exactly what its name implies it is. Voice calls (phone
calls) are made using a broadband Internet connection (such as a cable or
DSL modem), and instead of being routed through the Public Switched
Telephone Network (PSTN) — the phone network run by companies such as
AT&T and Verizon — they are routed across the Internet (or across private
networks, perhaps run by those same phone companies that run on the
Internet Protocol, IP).
Chances are good that you’ve already made a VoIP phone call — even if you
don’t know that you did. For example, many discount phone card companies,
alternative long-distance providers, and even the biggest of phone companies
use VoIP in part or all of their network. They do this because it’s cheaper and
more efficient to route phone calls this way than it is using the old-fashioned
phone network. So many phone companies will use traditional phone lines on
the ends of calls (from the local phone company office to your home) but use
VoIP in the core of the network.
You’ve also made a VoIP phone call if you’ve ever used the voice functionality
in an instant messenger program. For example, Yahoo! Messenger, AOL IM
(AIM), Google Talk, and Microsoft’s Windows Live Messenger all let you make
VoIP calls from computer to computer over the Internet. Many of these services
also let you make calls to standard phone numbers (for a fee).