Wilan LIBRA 5800 AP, Руководство пользователя

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Glossary
140 Libra 5800 Series User Guide
N
Near Line of Sight (NrLOS): Suburban
NrLOS is a visually-obstructed line of sight between two transmitting devices but a straight line can
still be drawn between them. Any combination of reflection, refraction and diffraction on a direct ray
between the transmitter and receiver may have occurred.
Non Line of Sight (NLOS): Dense Urban
No line can be drawn between two transmitting devices. Total visual blockage has occurred between
the transmitting and receiving devices. Extremely large amounts of reflection, refraction and
diffraction can occur on a direct ray between the transmitter and receiver.
null
An RF signal component with a smaller amplitude than the rest of the RF signal in multipath
interference. Nulls are caused by subtractive combination as a result of multipath fading.
null depth
The ratio in dB between the strongest OFDM carrier and the weakest carrier in multipath
interference. A null depth of zero indicates that there is no multipath reception.
O
Obstructed Line of Sight (OLOS): Urban
OLOS is a partially blocked elliptical cylinder, whose diameter depends on frequency and distance,
that can be drawn between two transmitting devices. An object is infringing or cutting into the
cylinder. OLOS can occur in various degrees of severity. Large amounts of reflection, refraction and/
or diffraction occur on a direct ray between the transmitter and receiver.
ODU
Outdoor Unit. This device sits between the Indoor Unit and the antenna. It converts signals from one
into the form needed by the other.
OFDM
Orthogonal Frequency Division Multiplexing. A method of splitting the data stream into a number of
channels, each transmitted simultaneously on a different frequency.
OFDM Station Type
Configuration setting where the base and remote are defined. The APs are base stations. The CPEs
are remote stations.
OID nodes
Object Identifier Nodes. These are the individual nodes in an MIB. See SNMP and MIB.