User's Manual

SPEEDLAN 9000 Series Installation and Operation User Guide Version 3.03
Glossary-5
Data Communication Equipment (DCE)
A definition of an interface standard that determines how it is connected to another device. For most
modems, it resolves issues of interface between Data Terminal Equipment (DTE) and the network.
Data Terminal Equipment (DTE)
Hardware that provides for data communications. See also DCE above.
dBm
Decibels (dB) relative to 1 milliwatt.
dBw
Decibels (dB) relative to 1 watt.
Decibel (dB)
The standard unit of measurement for expressing relative signal power. It is dimensionless and is instead
referenced to a certain level.
DHCP
DHCP servers provide efficient use of IP addresses by assigning them dynamically or statically to the wireless
router location. DHCP allows network administrators to dynamically assign IP addresses for the period of
time needed to connect to the Internet or network. By providing a DHCP server within the CPE and the base
station, the SPEEDLAN 9000 series allows the DHCP transactions to be handled locally at the remote
building. This reduces the load on the entire wireless network.
Diffraction
The distortion of a wave as it is partially obstructed by an object in its path.
Digital Signal Processor (DSP)
A specialized computer chip designed to perform speedy and complex operations on digitized waveforms.
Direct Sequence (DS)
A type of spreading technique that multiplies a higher rate PN code to the signal in order to spread the
energy of the narrow band signal over a much wider bandwidth for transmission.
Direct Sequence Speed Spectrum (DSSS)
DSSS may be seen as the result of two processes. Data is multiplied with a higher rate digital sequence
(spreading code). The sequence has many “chips” for every data bit. The resultant signal modulates the RF
carrier.