Nera WiLink-I 3000, Системное руководство

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214 WiLink-I Modular Base Station System Manual
NMS Network Management System. A system responsible for managing at
least part of a network. An NMS is generally a reasonably powerful
and well-equipped computer, such as an engineering workstation.
NMSs communicate with agents to help keep track of network
statistics and resources.
NOC
Network Operations Center. The physical space from which a
typically large telecommunications network is managed, monitored
and supervised.
NPU
Network Processing Unit
NRT Non Real Time. is very similar to the Real-Time polling service except
that connections may utilize random access transmit opportunities
for sending bandwidth requests. These Non Real Time Variable Bit
Rate (NRT-VBR) services, such as file transfer and Internet access
with a minimum guaranteed rate, are characterized by requirement
for a guaranteed rate, but can tolerate longer delays and are rather
insensitive to jitter. Service parameters include CIR, Committed
Time (CT), and MIR that limit the rate as otherwise bandwidth
intensive services may expand to occupy full bandwidth.
OA&M
Operation, Administration & Maintenance. Provides the facilities
and the personnel required to manage a network.
ODU
Outdoor Unit
OFDM
Orthogonal Frequency Division Multiplexing: A method for
multiplexing signals, which divides the available bandwidth into a
series of frequencies known as tones. Orthogonal tones do not
interfere with each other when the peak of one tone corresponds
with the null. The rapid switching, frequency-hopping technique is
intended to allow more robust data service.
OOB
Out-Of-Band
PER Packet Error Rate. In a digital transmission, PER is the percentage
of packets with errors divided by the total number of packets that
have been transmitted, received or processed over a given time
period.
PHY
PHYsical Layer. The physical, or lowest, layer of the OSI Network
Model. In a wireless network, the PHY defines parameters such as
data rates, modulation method, signaling parameters,
transmitter/receiver synchronization, etc. Within an actual radio
implementation, the PHY corresponds to the radio front end and
baseband signal processing sections.