Easy Mode; Sbas And Rtcm; Gnss Antenna - SimCom SIM68R Hardware Design

EASY MODE

4.6.2
EASY is the abbreviation of Embedded Assist System, it works as embedded firmware which accelerates TTFF
by predicting satellite navigation messages from received ephemeris.
No additional computing interval for EASY task. EASY is efficiently scheduled and computed in free time of
every second after GPS navigation solution.
EASY function is conceptually designed to automatically engage for predicting after first receiving the broadcast
ephemeris. After a while （generally tens of seconds）, 3-day extensions will be completely generated then all
EASY functions will be maintained at a sleep condition. EASY assistance is going to be engaged when the GPS
requests in new TTFF condition or re-generates again with another new received ephemeris. Meanwhile, TTFF
will be benefited by EASY assistance.
Note: EASY function is default open and can be closed by PMTK command.

SBAS and RTCM

4.6.3
SBAS is the abbreviation of Satellite Based Augmentation System. The SBAS concept is based on the
transmission of differential corrections and integrity messages for navigation satellites that are within sight of a
network of reference stations deployed across an entire continent. SBAS messages are broadcast via geostationary
satellites able to cover vast areas.
Several countries have implemented their own satellite-based augmentation system. Europe has the European
Geostationary Navigation Overlay Service (EGNOS) which covers Western Europe and beyond. The USA has
its Wide Area Augmentation System (WAAS). Japan is covered by its Multi-functional Satellite Augmentation
System (MSAS). India has launched its own SBAS program named GPS and GEO Augmented Navigation
(GAGAN) to cover the Indian subcontinent.
SIM68R module supports SBAS and RTCM, but only one mode can be applied at one time, and SBAS is the
default feature, customers who want to apply RTCM in the design can contact SIMCom sales for supporting
4.7

GNSS Antenna

The SIM68R is designed for use with passive and active antennas.
Table 6: Antenna Specifications
Parameter
Active Antenna Recommendations
SIM68R_Hardware Design_V1.02
Specification
Frequency range
Polarization
Gain
Noise Figure
19
Smart Machine Smart Decision
Passive and active antenna
1574～1606MHz
RHCP
20dB<Gain<30dB
<1.5 dB
2013-01-22