Wilan LIBRA 5800 AP, User Manual

Page: 135 / 156

June 2003 Rev 0 135
CPE
Customer Premise Equipment – the remote or subscriber unit in the Wi-LAN Broadband Wireless
Access System.
co-location
Placing antennas in the same place. One rooftop may host up to six antennas, each attached to a
different AP ODU and IDU.
coaxial cable
A type of wire that has an inner conductor surrounded by an outer conductor. The outer conductor
also serves as an electrical shield.
collision
A collision occurs when two devices send signals over the same medium at the same frequency at
the same time.
community names
A kind of password. The Public Community Name offers read-only SNMP access to the AP and CPE
IDUs. The Private Community name grants write access.
configuration menus
The menus in the user interface on the Access Points that allows the operator to view and configure
their parameters.
Cross-polarization discrimination
This specifies the signal isolation achieved when the receiving element of an antenna is
perpendicular to the radiating element. This is important when co-locating Access Points.
D
dB
Decibel. A relative measure used to specify power gains and losses. The difference between power
P1 and power P2 expressed in dB is:
DB-9
A D-shaped connector to the serial port on Wi-LAN equipment, with nine pins. Used to connect the
IDU and PC.
dBd
dBd is antenna gain referenced over a half-wave dipole. This is an antenna with a doughnut-shaped
radiation pattern.
Gain of a Standard Dipole = 2.14 dBi.
dB 10 P 1 P 2
⁄ ( )
log =