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Don™t forget about your personal digital assistant (PDA), if you™re lucky
enough to own one of those little gems. Wireless adapters are available that
fit into the Compact Flash slot in a typical PDA that enable you to connect
your palm-sized computer to your home network. (Hop to Chapter 3 for the
lowdown on different types of wireless connectivity.)

And if you™re an audiophile or just like to have fun, you should consider
adding your home digital entertainment system to your network so that you
can share MP3 files, play video games, and watch DVDs from anywhere in
your house, wirelessly! (These cool gadgets are covered in Chapters 11
through 13.)
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Chapter 4: Planning a Wireless Home Network


Choosing wired or wireless
You must decide whether you will connect each computer and network-
aware device wirelessly to the network or perhaps connect one or more by a
wired connection. At first glance, this decision might seem obvious. You™d
expect us to always recommend using wireless because this is a book about
wireless networks; however, using both a wired and a wireless connection can
sometimes make the most sense.

Wireless network devices and wired network devices can be used on the
same network. Both talk to the network and to each other using a protocol
known as Ethernet. (You should be getting used to that term by now if you™ve
been reading from the start of the book. If not, read through Chapters 1 and 2
for more about networking technology.)

The obvious and primary benefit of connecting to a network wirelessly is that
you eliminate wires running all over the place. But if two devices are sitting
on the same desk or table ” or are within a few feet of each other ” connect-
ing them wirelessly might be pointless. You can get Ethernet cables for $5 or
less; an equivalent wireless capability for two devices might top $100 when
everything is said and done. Keep in mind, however, that your computer
must have a wired network adapter installed to be able to make a wired con-
nection to the network. Fortunately, wired network adapters are dirt cheap
these days. Many new computers come with one installed as a standard fea-
ture (at no additional charge).

Figure 4-1 shows a simple drawing of a network that connects a wireless PC
to a wired PC through two network devices: an access point (AP) and a hub
or switch. (Recall that your AP connects wireless devices to the rest of the
wired network. A network hub or switch is often used to connect PCs to the
network by a wired connection. In Chapter 1, we describe the purpose of and
differences between APs and hubs and switches.) If you think that it seems
absurd to need two network devices to connect two computers, you™re not
alone. Hardware manufacturers have addressed this issue by creating APs
that have a built-in switch. See the “Choosing an access point” section later in
this chapter for more about these multi-function APs.




Figure 4-1:
A network
can use
both
Wireless PC
wireless Wire
and wired
AP Hub PC
connections.
68 Part II: Making Plans


Choosing a wireless technology
After you decide that you want to connect a PC to the network wirelessly,
choose a wireless technology to use. As we discuss extensively in Chapter 2,
the three leading wireless technologies used to connect a computer to a
home network are most often referred to by their technical names: Institute
of Electrical and Electronics Engineers (IEEE) 802.11a, IEEE 802.11b, and IEEE
802.11g. The marketing name for the first two technologies is Wi-Fi, which is a
brand name coined by a wireless trade group. Wi-Fi is supposed to denote
wireless fidelity. Apparently, some marketing guru seems to think that people
still remember the term Hi-Fi, which means high fidelity. We don™t know about
you, but we haven™t heard that term used by normal humans since Wally told
the Beaver to leave his Hi-Fi alone.

The discussion of wireless technology quickly degenerates into a sea of acro-
nyms and techno-speak. If you need a refresher on all this alphabet soup ”
or to begin from square one ” Chapter 2 is a primer on jargon, abbreviations,
and other nuts-and-bolts issues.

For home users, the three most important practical differences between
IEEE 802.11a, IEEE 802.11b, and IEEE 802.11g networks are speed, price, and
compatibility:

IEEE 802.11a equipment is typically more expensive than similar IEEE
802.11b equipment but is at least five times faster.
IEEE 802.11g is as fast as IEEE 802.11a but is almost as cheap as IEEE
802.11b.
IEEE 802.11a and IEEE 802.11b are not compatible.
IEEE 802.11b and IEEE 802.11g are compatible.

Because 802.11g is compatible with 802.11b, an AP that includes 802.11g
should work with any 802.11b device as well (at the lower 11 Mbps speed of
802.11b). Thus, you don™t have to look for a dual-mode 802.11b-and-802.11g AP.

If your primary reason for networking the computers in your house is to
enable Internet sharing, IEEE 802.11b is more than fast enough because your
Internet connection probably won™t exceed the 11 Mbps of the 802.11b con-
nection anytime soon; it probably hovers in the sub-1 Mbps range. However,
if you don™t mind spending a little extra money (in some cases, very little
extra), you can be ready for anything that the home electronics and broad-
band Internet services providers can throw at you. And, if you™re a gamer and
into graphics-intensive, multi-user intergalactic battles or dream of watching
real-time streaming video over a broadband connection, your need for speed
will be worth shelling out the extra bucks to get it. Finally, if you plan on
having any servers at home, such as a home server for your DVDs, then
you™ll want the higher bandwidth.
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Chapter 4: Planning a Wireless Home Network

If you want to hedge your bets, look for an AP that can handle both IEEE
802.11a and IEEE 802.11b/g technology standards. Linksys, NETGEAR, D-Link,
and several other leading manufacturers of wireless home networking equip-
ment already offer a/b/g dual-mode, tri-standard wireless devices.



Choosing an access point
The most important and typically most expensive device in a wireless net-
work is the access point (AP; also sometimes called a base station). An AP
acts like a wireless switchboard that connects wireless devices on the net-
work to each other and to the rest of the wired network; it™s required to
create a wireless home network. Figure 4-2 depicts three PCs connected wire-
lessly to each other through an AP.




Figure 4-2:
Three PCs
Wireless PCs
connected
Wireless PC
wirelessly to AP
each other
through
an AP.



Choosing an AP that performs several additional network-oriented services
might also be economical for you. The most popular APs for use in home net-
works are those that can do one or more of the following:

Connect wired PCs: A switch is an enhanced version of a hub that oper-
ates more efficiently and quickly than a simple hub. By building a switch
inside the AP, you can use the one device to connect PCs to your net-
work by using either wired network adapters or wireless adapters. We
cover hubs and switches in more detail in Chapter 1.
Assign network addresses: Every computer on a network or on the
Internet has its own address: its Internet Protocol (IP) address.
Computers on the Internet communicate ” forwarding e-mail, Web
pages, and the like ” by sending data back and forth from IP address to
IP address. A Dynamic Host Configuration Protocol (DHCP) server dynam-
ically assigns private IP addresses to the computers on your home net-
work so that they can communicate. You could use a software utility in
70 Part II: Making Plans

Windows (or Mac OS) to manually assign an IP address to each com-
puter, but that process is tedious and much less flexible than automatic
address assignment.
Connect to the Internet: With a cable/digital subscriber line (DSL) router
between a broadband modem and your home network, all computers on
the network can access the Internet directly. An AP combined with a
DHCP and cable/DSL router is sometimes called a wireless Internet gate-
way. (See the “Connecting to the Internet” section later in this chapter
for more about the Network Address Translation [NAT] feature that
makes Internet sharing possible and for more on Internet connectivity.)
Add a print server: A print server enables you to connect a printer
directly to the network rather than connecting it to one of the computers
on the network. See the “Adding printers” section later in this chapter.
Connect in many ways: The most common method of connecting an AP
to your computer or to the wired portion of your network is through an
Ethernet port, but other options may be much easier to install if your
house isn™t wired with Ethernet cable. If you™ve created a HomePNA
wired network by using the phone lines in your home, look for an AP
that has a HomePNA port. Similarly, if you have set up a HomePlug
wired network using the power lines in your home, shop for an AP with
HomePlug connectivity. (For more on HomePNA and HomePlug, skip to
Chapter 3.)
Access points with HomePlug built into them are very handy when you
want to add a second AP to your network in a remote part of the house
(somewhere that doesn™t get good coverage from your main AP). With
HomePlug, you can plug a small device (like Siemens™ SpeedStream 2521
[www.speedstream.com]) into the wall and have an instant extra access
point with no special connections at all. (You™ll need to have HomePlug
in your main AP or router to make this work, of course.)
Provide firewall security: A firewall is a device that basically keeps the
bad guys off your network and out of your computers. We talk a lot more
about firewalls in Chapter 10, but basically, a firewall might be included
in your access point to provide network security.
Be combined with a modem: If you™re a cable Internet or DSL sub-
scriber, you might be able to use your own modem instead of leasing
one from your Internet service provider (ISP). In that case, consider pur-
chasing a modem that™s also a wireless AP. A cable or DSL modem com-
bined with a wireless Internet gateway is the ultimate solution in terms
of installation convenience and equipment cost savings.
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Chapter 4: Planning a Wireless Home Network


Deciding where to install the AP
If you™ve ever experienced a dreaded dead zone while talking on a cellular
phone, you know how frustrating that can be. Similarly, you should strive to
install your wireless network in a way that eliminates dead wireless network
zones in your house. Ideally, you determine the best placement of your AP so
that no spot in your house is left uncovered; but, if that isn™t possible for
some reason, you should at least find out where, if anywhere, the dead zones
in your house are to optimize your signal coverage.

To achieve optimum signal coverage, the best place to install an AP is near the
center of your home. Think about where you will place the AP when you make
your buying decision. All APs can sit on a shelf or table, but some APs can also
be mounted to a wall or ceiling. When making your AP selection, ensure that it
can be installed where it works best for the configuration of your house as
well as keep the AP out of reach of your little ones or curious pets.

The position of the access point is critical because your entire signal foot-
print emanates from the AP in a known way, centered from on the AP™s
antenna(s). Sometimes not enough consideration is given to the positioning
of the access point because they so often work pretty well out of the box, just
sitting on a table.

Other people install it wrong in the first place. For instance, probably one
of the worst manufacturing decisions ever done to access points was to
put mounting brackets on them. People get the impression that you should
then ” duh ” mount them on the wall. That™s great except for the fact that,
depending on the antenna you have, you might just kill most of your through-
put. You see, when an antenna is flush up against a wall, as is typical in a wall
mount situation, the signals of the antenna reflect off the wall back at the
antenna, causing interference, and driving down throughput precipitously.
Yech. (But you see, customers WANT their wall mount brackets, so product
managers at wireless LAN companies decided they had to give it to them.)
The best mounting is actually six or more inches off the wall.

The vertical orientation of the mounting point is important as well. Generally,
you have more interference lower to the ground. If you did a cross section of
your house in one-foot intervals, when you get higher and higher, you™d see
less on your map. Thus, signals from an access point located on a shelf low to
the ground are going to find more to run into than the ones that are mounted
higher. Although this might sound like common sense, consider that most
DSL and cable modems are installed by technicians who are used to installing
phone and cable TV lines. How many of these are generally located five feet
off the floor? They™re not; they tend to be along the floorboards and low to
the ground or in the basement. So it™s not surprising that a combined DSL
access point router would be plugged in low to the ground, too.
72 Part II: Making Plans

See where we are going with this? You don™t care where your cable modem is,
but you should care where your AP functionality is located. And if you have
an integrated product, you™re probably tempted to swap out the cable
modem for the cable modem access point. Simply moving that unit higher
will do a world of good.

Moving an AP out of the line of sight of microwaves, cordless phones, refrig-
erators, and so on is a good idea, too. Mounting the AP in the laundry room
off the kitchen does not make a great deal of sense if you will primarily use
the AP in rooms on the other side of the kitchen. In general, passing through
commonly used interferers (all those metal appliances) like that is not a
smart move.




Wireless interference in the home

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