19216811.liveASCII is the acronym for the
American Standard Code for Information Interchange
. Pronounced
ask-ee
, ASCII is a code for
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 is an upgrade to the WEP (Wired Equivalent Privacy) 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 TKIP (Temporal Key Integrity Protocol) encryption to address the vulnerabilities of
the static keys used in WEP (Wired Equivalent Privacy). TKIP includes four algorithms: MIC (message integrity check), to
protect packets from tampering; PPK (Per-Packet Key) hashing, to prevent weak key attacks; extended IV (initialization vector),
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, TrueMobile 2300 also supports AES (Advanced Encryption Security) encryption. AES will
replace 802.11's RC4-based encryption under 802.11i specification. AES, the gold-standard encryption algorithm, provides
maximum security for wireless network.
For user authentication, WPA adopts an authentication scheme -- via 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 wireless router and authentication server. In Small Office/ Home
Office (SOHO) environment, where there are no authentication server, users can use pre-shared key (PSK) mode in place of
the authentication server. TrueMobile 2300 offers you WPA running in PSK mode. The mutual authentication and improved
encryption technology of WPA allows wireless communication to achieve greater security.
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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 Wireless 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 WLAN.
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