SE868-V3 Product User Guide
1VV0301205 r4 – 2016-01-20
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights Reserved.
Page 73 of 76
Mod. 0805 2015-02 Rev.4
NMEA
: National Marine Electronics Association
QZSS
: Quasi-Zenith Satellite System
The Japanese
SBAS
system (part of MSAS).
Reacquisition
: A receiver, while in normal operation, loses RF signal (perhaps due to the
antenna cable being disconnected or a vehicle entering a tunnel), and re-establishes a valid fix
after the signal is restored. Contrast with
Reset
and
Restart.
Restart
: A receiver beginning operation after being sent a restart command, generally used for
testing rather than normal operation. A restart can also result from a power-up. See
Cold Start,
Warm Start,
and
Hot Start.
Contrast with
Reset
and
Reacquisition.
Reset:
A receiver beginning operation after a (hardware) reset signal on a pin, generally used
for testing rather than normal operation
.
Contrast with
Restart
and
Reacquisition.
RoHS:
The Restriction of Hazardous Substances
Directive on the restriction of the use of certain hazardous substances in electrical and electronic
equipment, was adopted in February 2003 by the European Union.
RTC
: Real Time Clock
An electronic device (chip) that maintains time continuously while powered up.
SAW
: Surface Acoustic Wave filter
Electromechanical device used in radio frequency applications. SAW filters are useful at
frequencies up to 3 GHz.
SBAS
: Satellite Based Augmentation System
A system that uses a network of ground stations and geostationary satellites to provide
differential corrections to GNSS receivers. These corrections are transmitted on the same
frequency as navigation signals, so the receiver can use the same front-end design to process
them. Current examples are
WAAS, EGNOS, MSAS,
and
GAGAN
.
Server-based Ephemeris prediction data
:
Extended Ephemeris (i.e. predicted) data, calculated by a server and provided to the receiver
over a network. It is usually useful for up to 14 days. See
AGPS.
TCXO
: Temperature-Compensated Crystal Oscillator
Tracking Sensitivity
:
The lowest signal level at which a
GNSS
receiver is able to maintain tracking of a satellite
signal after acquisition is complete.
TTFF
: Time to First Fix
The elapsed time required by a receiver to achieve a valid position solution from a specified
starting condition. This value will vary with the operating state of the receiver, the length of
time since the last position fix, the location of the last fix, and the specific receiver design. A
standard reference level of -130 dBm is used for testing.
