RD Glossary
D
- data
- Information, such as electronic files, that is stored and sent over a wireless network. Often data are sent in multiple packets, which are sent separately through the network.
- data rate
- The number of bits per second (bps) that data is sent. For example, 802.11b wireless LANs operate at up to 11Mbps.
- DCF (distributed coordination function)
- A part of the 802.11 standard that defines how stations will contend for access to the air medium. DCF makes use of CSMA to regulate traffic on the network.
- DHCP (Dynamic Host Configuration Protocol)
- A protocol that automatically assigns unique IP addresses within an assigned range to network devices. Most home and public wireless LANs implement DHCP, making it very easy for users to gain access to the network. DHCP automatically assigns a valid IP address to these users.
- digital certificate
- An electronic message that contains the credentials of a particular user. Digital certificates are used as a means for authenticating users or their computer devices.
- digital signal
- A signal that varies in amplitude steps as time advances. Digital signal represent data within a computer device. The digital signal must be converted to an analog form (know as modulation) before the data can be sent through the air medium.
- direct sequence spread spectrum
- A type of spread spectrum where a spreading code increases the signal rate of the data stream in order to spread the signal over a wider portion of the frequency band. 802.11b wireless LANs make use of direct sequence.
- directional antenna
- A type of antenna that focuses radio waves and range more in one direction than others. Directional antennas are commonly found in wireless MANs and wireless WAN systems. The directivity of the antenna increases range in one direction and decreases range in other directions.
- distribution system
- A wired system that physically interconnects access points in a wireless LAN. A common distribution system for wireless LANs, for example, is Ethernet.
RD Glossary by Run Digital
