Asus WL-320gP User Manual - Page 53

Chapter 5 - Appendix lower-speed subcarriers, which are then transmitted in parallel. Each highspeed carrier is 20 MHz wide and is broken up into 52 subchannels, each approximately 300 KHz 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 300 KHz wide. At the low end of the speed gradient, BPSK (binary phase shift keying) is used to encode 125 Kbps of data per channel, resulting in a 6,000-Kbps, or 6 Mbps, data rate. Using quadrature phase shift keying, you can double the amount of data encoded to 250 Kbps per channel, yielding a 12-Mbps data rate. And by using 16-level quadrature amplitude modulation encoding 4 bits per hertz, you can achieve a data rate of 24 Mbps. 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 24 Mbps. 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. Device Name Also known as DHCP client ID or network name. Sometimes provided by an ISP when using DHCP to assign addresses. DHCP (Dynamic Host Configuration Protocol) This protocol allows a computer (or many computers on your network) to be automatically assigned a single IP address from a DHCP server. DNS Server Address (Domain Name System) DNS allows Internet host computers to have a domain name and one or more IP addresses. A DNS server keeps a database of host computers and their respective domain names and IP addresses, so that when a user enters a domain name into the Internet browser, the user is sent to the proper IP address. The DNS server address used by the computers on your home network is the location of the DNS server your ISP has assigned. DSL Modem (Digital Subscriber Line) A DSL modem uses your existing phone lines to transmit data at high speeds. Direct-Sequence Spread Spectrum (for 802.11b) Spread spectrum (broadband) uses a narrowband signal to spread the transmission over a segment of the radio frequency band or spectrum. 5. Appendix ASUS 802.11g Access Point 53