Wi Lan Inc EB02 Benutzerhandbuch

  APR 2001 Rev 03

157

Antennas mounted too close to “soft” objects, such as trees, may experience a reduction 
in signal strength due to absorption. Absorption is most often encountered in 
applications installed during the fall or winter months. The problem does not become 
evident until the spring when leaves appear.

To minimize the effects of interference, all units in a system use the same acquisition 
code so the receivers can distinguish the desired signal from other interfering signals.

In an SNMP context, the agent runs on each unit. An agent accepts configuration 
commands from the manager and collects network and terminal information specified in 
the MIB.

A device which accepts electromagnetic energy from a circuit or wire and radiates it into 
space rather than confining it.

Gain of the antenna over a dipole (dBd) or isotropic (dBi).
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Antennas have a gain associated with them, which is a measure of their ability to 
amplify signals in their tuned band.

•

Antenna gain is achieved by focusing the signal. A higher gain antenna has more 
compressed signal.

Address Resolution Protocol. A low-level protocol that maps IP addresses to Ethernet 
addresses. An ARP request is sent out to the network along with an IP address. The node 
with the address responds to the request with a hardware address so the transmission 
can take place.

Any loss in signal strength, due to resistance, absorption, capacitance or any 
characteristic of the medium or design of the system.