Wireless Home Networking - Index of

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Part III: Installing a Wireless Network
Most 802.11g access points, such as some from Linksys, default to
Channel 6 as a starting point and detect other access points in the area
so that you can determine which channel to use. 802.11n access points
will dynamically switch channels and choose the channels with the least
interference automatically, which is cool.
Most 802.11n APs available today use only the 2.4 GHz frequency range.
They can use multiple channels in this range, switching dynamically
between channels if they find too much interference. The 2.4 GHz range
is also the same frequency as Bluetooth devices. All new 802.11n draft 2
APs have the option to work in a default mode, using only 20 MHz of
bandwidth inside the 2.4 GHz channel space (a single channel), or they
can use a combined pair of channels (providing 40 MHz of bandwidth).
Using combined (or bonded) channels allows your 802.11n gear to reach
greater data speeds and has the fringe benefit of helping your network
avoid interference with Bluetooth devices. If you use a lot of Bluetooth
devices around your computer — such as a Bluetooth headset, mouse,
keyboard, and camera — make sure you are in combined mode so that
your 802.11n connection does not affect your Bluetooth devices and
vice versa.
When you have multiple access points set to the same channel, sometimes
roaming doesn’t work when users move about the house, and the
transmission of a single access point blocks all others that are within
range. As a result, performance degrades significantly (you see this when
your throughput, or speed of file and data transfers, decreases noticeably.)
Use different, widely separated channels for 802.11g; because the 5 GHz
802.11a (and some 802.11n) channels are inherently not overlapping, you
don’t have to worry about choosing widely separated channels in this
case.
� WPA2: Wi-Fi Protected Access (WPA2) is one of the best solutions in
Wi-Fi security. Two versions of WPA are available:
• WPA2 Personal, or Pre-Shared Key (PSK), gives you a choice of
two encryption methods: TKIP (Temporal Key Integrity Protocol),
which utilizes a stronger encryption method and incorporates
Message Integrity Code (MIC) to provide protection against hackers,
and AES (Advanced Encryption System), which utilizes a symmetric
128-bit block data encryption. TKIP was the only system
available in the first version of WPA; WPA2 added the ability to use
AES, a stronger encryption system.
• WPA2 Enterprise, or RADIUS (Remote Authentication Dial-In User
Service) utilizes a RADIUS server for authentication and the use of
dynamic TKIP, AES, or WEP. RADIUS servers are specialized computer
devices that do nothing but authenticate users and provide
them with access to networks (or deny unauthorized users access).
If you don’t know what a RADIUS server is all about, chances are
good that you don’t have one.