standards and guidelines for communication sites - Radio And ...

GLOSSARY CHAPTER 1: INTRODUCTION
Material Safety Data Sheet: A manufacturer-provided ingredient and safety hazard description of
materials classified as hazardous or containing hazardous elements. It also includes information for
handling spills or chemical reactions.
Maximum Permissible Exposure: Defines maximum permissible exposure to radiated RF energy
to personnel. Several levels exist based upon frequency, power density, and time of exposure.
Metal-Oxide Varistor: A two-terminal voltage protection device in which resistance across the
device markedly decreases when the voltage across the device reaches a specified threshold.
Meter pedestal: The base structure for the electric services utility meter at communications site.
Typically installed by the local utility company during communications facility construction.
MGB: Master Ground Bus Bar.
Microwave: Frequencies higher than one GigaHertz (1,000,000,000 Hz) in the frequency spectrum.
Mobile Switching Office: Provides central office functions for iDEN mobile units.
Modified Proctor test: A soil compression test that measures the compacted density of soils being
used for structural applications. (See ASTM D1557 for additional information.)
MOV: Metal-Oxide Varistor.
MPE: Maximum Permissible Exposure.
MSDS: Material Safety Data Sheet.
MSO: Mobile Switching Office.
MTBF: Mean Time Between Failures.
Multicoupler: An RF device which provides multiple outputs of a single RF input.
Multimeter: A test instrument capable of measuring voltage, current, and resistance.
National Electrical Code: A consultative organization responsible for electrical practices standards.
It is part of the National Fire Protection Association (NFPA).
NEBS: Network Equipment Building Systems.
NEC ® : National Electrical Code.
Network Interface Unit: A T-1 network interface unit.
NCRP: National Council for Radio Protection and Measurement.
NEMA: National Electrical Manufacturers Association.
NFPA: National Fire Protection Association.
NIU: Network Interface Unit.
Noise: Regarding line power, a power line abnormality which collectively refers to various kinds of
high frequency impulses that ride on the normal sine wave of AC electrical power. Noise can range
from a few millivolts to several volts in amplitude and can create erratic behavior in any electronic
circuit. RF noise, when present over power lines, is one of the more troublesome. This noise can be
generated by lightning, radio transmissions, or computer power supplies.
Nomograph: An arrangement of axes in which a variable is determined by a line which intersects
known points on associated axes.
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