D-6
InterReach Unison Installation, Operation, and Reference Manual
CONFIDENTIAL
D-620003-0-20 Rev J
to wireless operators to provide service within these MTAs and/or BTAs. (See
BTA.)
Multiplexing
The simultaneous transmission of two or more signals on the same
radio (or other) transmission facility.
N-AMPS
Narrowband Advanced Mobile Phone Service.
PCMCIA
Personal Computer Memory Card International Association. This acro-
nym is used to refer to credit card sized packages containing memory, I/O
devices and other capabilities for use in Personal Computers, handheld comput-
ers and other devices.
PCS
Personal Communications Service. A vague label applied to new-generation
mobile communication technology that uses the narrow band and broadband
spectrum recently allocated in the 1.9 GHz band.
PDA
Personal Digital Assistant. Portable computing devices that are extremely por-
table and that offer a variety of wireless communication capabilities, including
paging, electronic mail, stock quotations, handwriting recognition, facsimile, cal-
endar, and other information handling capabilities.
PDC
Personal Digital Cellular (formerly Japanese Digital Cellular). A
TDMA-based digital cellular standard that operates in the 1500 MHz band.
Phase
The particular angle of inflection of a wave at a precise moment in time. It is
normally measured in terms of degrees.
PHS
Personal Handyphone System. A wireless telephone standard, developed and
first deployed in Japan. It is a low mobility, small-cell system.
POP
Short for “population”. One person equals one POP.
POTS
Plain Old Telephone Service.
PSTN
Public Switched Telephone Network. Refers to the international telephone
system and includes both local and long distance networks.
Reverse Channel
Refers to the radio channel that sends information from a mobile
station to a base station. (See Forward Channel.)
RF
Radio Frequency. Those frequencies in the electromagnetic spectrum that are
associated with radio wave propagation.
Roaming
The ability to use a wireless phone to make and receive calls in places
outside one's home calling area.
RSA
Rural Service Area. One of the 428 FCC-designated rural markets across the
United States used as license areas for cellular licenses. (See MTAs and BTAs.)
Sector
A portion of a cell. Often, different sectors within the same cell will each use
a different set of frequencies to maximize spectrum utilization.
