ASUS usb-n53 wi-fi adapter usbn53 사용자 설명서

ASUS Wireless Dual-band Adapter

Signal power alone is not enough to maintain 802.11b-like distances in an 

802.11a/g environment. To compensate, a new physical-layer encoding technology 

was designed that departs from the traditional direct-sequence technology being 

deployed today. This technology is called COFDM (coded OFDM). COFDM was 

developed specifically for indoor wireless use and offers performance much 

superior to that of spread-spectrum solutions. COFDM works by breaking one 

high-speed data carrier into several lowerspeed subcarriers, which are then 

transmitted in parallel. Each high-speed carrier is 20MHz wide and is broken 

up into 52 subchannels, each approximately 300KHz wide. COFDM uses 48 of 

these subchannels for data, while the remaining four are used for error correction. 

COFDM delivers higher data rates and a high degree of multipath reflection 

recovery, thanks to its encoding scheme and error correction.
Each subchannel in the COFDM implementation is about 300KHz wide. At the 

low end of the speed gradient, BPSK (binary phase shift keying) is used to 

encode 125Kbps of data per channel, resulting in a 6,000Kbps, or 6Mbps, data 

rate. Using quadrature phase shift keying, you can double the amount of data 

encoded to 250Kbps per channel, yielding a 12Mbps data rate. And by using 

16-level quadrature amplitude modulation encoding 4bits per hertz, you can 

achieve a data rate of 24Mbps. The 802.11a/g standard specifies that all 802.11a/

g-compliant products must support these basic data rates. The standard also lets 

the vendor extend the modulation scheme beyond 24Mbps. Remember, the more 

bits per cycle (hertz) that are encoded, the more susceptible the signal will be to 

interference and fading, and ultimately, the shorter the range, unless power output 

is increased.

This option allows you to select the default WEP key. This option allows you to 

use WEP keys without having to remember or write them down. The WEP keys 

generated using the Pass Phrase is compatible with other WLAN products. The 

Pass Phrase option is not as secure as manual assignment.

Also known as DHCP client ID or network name. Sometimes provided by an ISP 

when using DHCP to assign addresses.

This protocol allows a computer (or many computers on your network) to be 

automatically assigned a single IP address from a DHCP server.