User's Manual

124 Glossary TB9300 Installation and Operation Manual
© Tait Limited March 2017
TIA Telecommunications Industry Association
toggle Describes the switching between two states. If something is on, toggling it
turns it off. If it is off, toggling it turns it on.
tone A sound wave of a particular frequency.
Tx Transmitter.
UDP User Datagram Protocol. A simple protocol on top of IP for sending
streams of data.
uplink The transmission path from mobile stations to fixed equipment.
UTC Coordinated Universal Time (word order from French). An international
time standard that has replaced Greenwich Mean Time.
valid signal A signal that the receiver unmutes to. A signal is valid, for example, when
it is strong enough to be decoded and when it has the specified NAC.
VDP Voice Data Protocol. A proprietary protocol operating over IP for the
exchange of voice and data between a base station and a trunking node
controller.
voice stream A digitized voice signal that passes through the main switch.
VoIP Voice over IP. The name for the technology that puts speech signals in
packets and then routes them over an IP backbone network.
VPN Virtual Private Network. A private communications network used to
communicate confidentially over a non-private network.
VSWR Voltage Standing Wave Ratio is the ratio of the maximum peak voltage
anywhere on the transmission line to the minimum value anywhere on the
transmission line. A perfectly matched line has a VSWR of 1:1. A high
ratio indicates that the antenna subsystem is poorly matched.
watchdog A circuit that checks that the system is still responding. If the system does
not respond (because the firmware has locked up), the circuit generally
resets the system.