Automatic rate selection and rate scaling – Dell 2350 Wireless Broadband Router User Manual
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representing English characters as numbers, with each letter assigned a number from 0 to 127. For example, the ASCII code
for uppercase M is 77. Most computers use ASCII codes to represent text, which makes it possible to transfer data from one
computer to another.
WPA
WPA (Wi-Fi Protected Access) is an upgrade to the WEP standard for securing your wireless network. WPA is derived from
and will be forward-compatible with the future IEEE 802.11i standard. It provides improved data encryption and user
authentication.
To enhance the level of security, WPA uses Temporal Key Integrity Protocol (TKIP) encryption to address the vulnerabilities
of the static keys used in WEP. TKIP includes four algorithms: Message Integrity Check (MIC), to protect packets from
tampering; Per-Packet Key (PPK) hashing, to prevent weak key attacks; extended Initialization Vector (IV), to reduce IV
reuse and the possibility that a hacker will collect sufficient packets to crack the encryption; and a re-keying mechanism, to
change the temporal key dynamically. TKIP is the most commonly used encryption method; however, if your wireless clients do
not support TKIP, the Dell Wireless 2350 Broadband Router also supports Advanced Encryption Security (AES) encryption.
AES will replace 802.11's RC4-based encryption under the 802.11i specification. AES, the gold-standard encryption algorithm,
provides maximum security for a wireless network.
For wireless client authentication, WPA adopts an authentication scheme through 802.1x. 802.1x provides a framework for user
authentication and a key distribution management method. 802.1x consists of three main elements: an Authentication Server
(typically a RADIUS server), WPA-enabled router or AP (called Authenticator), and a WPA-enabled client (called Supplicant).
802.1x ensures only authorized users can access the network.
In enterprises, WPA will be used in conjunction with both a wireless router and authentication server. In a Small Office/Home
Office (SOHO) environment, where there is no authentication server, users can use Pre-Shared Key (PSK) mode in place of
the authentication server. The Dell Wireless 2350 Broadband Router offers you WPA running in PSK mode. The mutual
authentication and improved encryption technology of WPA allows wireless communication to achieve greater security.
Automatic Rate Selection and Rate Scaling
In 802.11g, wireless network adapters and access points can transmit data at one of the following rates: 54, 48, 36, 24, 18, 12,
9, or 6 Mbps. In 802.11b, the data can be transmitted at a rate of 11, 5.5, 2, or 1 Mbps. As the distance between an adapter
and access point increases or decreases, the data rate automatically changes. Other factors, like interference, also affect the
data rate. The Dell Wireless 2350 Broadband Router uses automatic rate selection and rate scaling to determine the most
efficient rate of communication. Rate scaling maintains optimal communication between wireless clients and the Dell Wireless
2350 Broadband Router.