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Reference Manual for the NETGEAR ProSafe Dual Band Wireless Access Point WAG302
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Wireless Networking Basics
202-10078-01
channels are 5 MHz apart. However, due to spread spectrum effect of the signals, a node sending
signals using a particular channel will utilize frequency spectrum 12.5 MHz above and below the
center channel frequency. As a result, two separate wireless networks using neighboring channels
(for example, channel 1 and channel 2) in the same general vicinity will interfere with each other.
Applying two channels that allow the maximum channel separation will decrease the amount of
channel cross-talk, and provide a noticeable performance increase over networks with minimal
channel separation.
The radio frequency channels used in 802.11b/g networks are listed in
Table B-2
:
Note:
The available channels supported by the wireless products in various countries are different.
For example, Channels 1 to 11 are supported in the U.S. and Canada, and Channels 1 to 13 are
supported in Europe and Australia.
The preferred channel separation between the channels in neighboring wireless networks is 25
MHz (5 channels). This means that you can apply up to three different channels within your
wireless network. There are only 11 usable wireless channels in the United States. It is
recommended that you start using channel 1 and grow to use channel 6, and 11 when necessary, as
these three channels do not overlap.
Table B-2:
802.11b/g Radio Frequency Channels
Channel
Center Frequency
Frequency Spread
1
2412 MHz
2399.5 MHz - 2424.5 MHz
2
2417 MHz
2404.5 MHz - 2429.5 MHz
3
2422 MHz
2409.5 MHz - 2434.5 MHz
4
2427 MHz
2414.5 MHz - 2439.5 MHz
5
2432 MHz
2419.5 MHz - 2444.5 MHz
6
2437 MHz
2424.5 MHz - 2449.5 MHz
7
2442 MHz
2429.5 MHz - 2454.5 MHz
8
2447 MHz
2434.5 MHz - 2459.5 MHz
9
2452 MHz
2439.5 MHz - 2464.5 MHz
10
2457 MHz
2444.5 MHz - 2469.5 MHz
11
2462 MHz
2449.5 MHz - 2474.5 MHz
12
2467 MHz
2454.5 MHz - 2479.5 MHz
13
2472 MHz
2459.5 MHz - 2484.5 MHz
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Reference Manual for the NETGEAR ProSafe Dual Band Wireless Access Point WAG302
Wireless Networking Basics
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802.11a Wireless Channels
IEEE 802.11a utilizes 300 MHz of bandwidth in the 5 GHz Unlicensed National Information
Infrastructure (U-NII) band. Though the lower 200 MHz is physically contiguous, the FCC has
divided the total 300 MHz into three distinct domains, each with a different legal maximum power
output.
The WAG302 user can use thirteen channels in non-turbo mode.
Table B-3:
802.11a Turbo Mode Off Radio Frequency Channels (Turbo Mode OFF)
Channel
Frequency
36
5.180 GHz
40
5.200 GHz
44
5.220 GHz
48
5.240 GHz
52
5.260 GHz
56
5.280 GHz
60
5.300 GHz
64
5.320 GHz
149
5.745 GHz
153
5.765 GHz
157
5.785 GHz
161
5.805 GHz
165
5.825 GHz
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Reference Manual for the NETGEAR ProSafe Dual Band Wireless Access Point WAG302
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Wireless Networking Basics
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The WAG302 user can use five channels in turbo mode.
The available channels supported by the wireless products in various countries are different.
WPA Wireless Security
Wi-Fi Protected Access (WPA) is a specification of standards-based, interoperable security
enhancements that increase the level of data protection and access control for existing and future
wireless LAN systems.
The IEEE introduced the WEP as an optional security measure to secure 802.11b (Wi-Fi) WLANs,
but inherent weaknesses in the standard soon became obvious. In response to this situation, the
Wi-Fi Alliance announced a new security architecture in October 2002 that remedies the
shortcomings of WEP. This standard, formerly known as Safe Secure Network (SSN), is designed
to work with existing 802.11 products and offers forward compatibility with 802.11i, the new
wireless security architecture being defined in the IEEE.
WPA offers the following benefits:
Enhanced data privacy
Robust key management
Data origin authentication
Data integrity protection
Table B-4:
802.11a Turbo Mode Off Radio Frequency Channels (Turbo Mode ON)
Channel
Frequency
42
5.21 GHz
50
5.25 GHz
58
5.29 GHz
152
5.76 GHz
160
5.8 GHz
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Reference Manual for the NETGEAR ProSafe Dual Band Wireless Access Point WAG302
Wireless Networking Basics
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The Wi-Fi Alliance is now performing interoperability certification testing on Wi-Fi Protected
Access products. Starting August of 2003, all new Wi-Fi certified products will have to support
WPA. NETGEAR will implement WPA on client and access point products and make this
available in the second half of 2003. Existing Wi-Fi certified products will have one year to add
WPA support or they will lose their Wi-Fi certification.
The 802.11i standard is currently in draft form, with ratification due at the end of 2003. While the
new IEEE 802.11i standard is being ratified, wireless vendors have agreed on WPA as an
interoperable interim standard.
How Does WPA Compare to WEP?
WEP is a data encryption method and is not intended as a user authentication mechanism. WPA
user authentication is implemented using 802.1x and the Extensible Authentication Protocol
(EAP). Support for 802.1x authentication is required in WPA. In the 802.11 standard, 802.1x
authentication was optional. For details on EAP specifically, refer to IETF's RFC 2284.
With 802.11 WEP, all access points and client wireless adapters on a particular wireless LAN must
use the same encryption key. A major problem with the 802.11 standard is that the keys are
cumbersome to change. If you do not update the WEP keys often, an unauthorized person with a
sniffing tool can monitor your network for less than a day and decode the encrypted messages.
Products based on the 802.11 standard alone offer system administrators no effective method to
update the keys.
For 802.11, WEP encryption is optional. For WPA, encryption using Temporal Key Integrity
Protocol (TKIP) is required. TKIP replaces WEP with a new encryption algorithm that is stronger
than the WEP algorithm, but that uses the calculation facilities present on existing wireless devices
to perform encryption operations. TKIP provides important data encryption enhancements
including a per-packet key mixing function, a message integrity check (MIC) named Michael, an
extended initialization vector (IV) with sequencing rules, and a re-keying mechanism. Through
these enhancements, TKIP addresses all of known WEP vulnerabilities.
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Reference Manual for the NETGEAR ProSafe Dual Band Wireless Access Point WAG302
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How Does WPA Compare to IEEE 802.11i?
WPA will be forward compatible with the IEEE 802.11i security specification currently under
development. WPA is a subset of the current 802.11i draft and uses certain pieces of the 802.11i
draft that are ready to bring to market today, such as 802.1x and TKIP. The main pieces of the
802.11i draft that are not included in WPA are secure IBSS (Ad-Hoc mode), secure fast handoff
(for specialized 802.11 VoIP phones), as well as enhanced encryption protocols, such as
AES-CCMP. These features are either not yet ready for market or will require hardware upgrades
to implement.
What are the Key Features of WPA Security?
The following security features are included in the WPA standard:
WPA Authentication
WPA Encryption Key Management
Temporal Key Integrity Protocol (TKIP)
Michael message integrity code (MIC)
AES Support (to be phased in)
Support for a Mixture of WPA and WEP Wireless Clients, but mixing WEP and WPA is
discouraged
These features are discussed below.
WPA addresses most of the known WEP vulnerabilities and is primarily intended for wireless
infrastructure networks as found in the enterprise. This infrastructure includes stations, access
points, and authentication servers (typically RADIUS servers). The RADIUS server holds (or has
access to) user credentials (for example, user names and passwords) and authenticates wireless
users before they gain access to the network.
The strength of WPA comes from an integrated sequence of operations that encompass 802.1X/
EAP authentication and sophisticated key management and encryption techniques. Its major
operations include:
Network security capability determination. This occurs at the 802.11 level and is
communicated through WPA information elements in Beacon, Probe Response, and (Re)
Association Requests. Information in these elements includes the authentication method
(802.1X or Pre-shared key) and the preferred cipher suite (WEP, TKIP, or AES).

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