Study on feasibility of SATCOM for railway communication

Final Report
Figure 20: Globalstar gateway antenna
In order to provide access, security, and roaming and billing services to users, all Globalstar gateways
have a Home Location Register (HLR) and a Visitor Location Register (VLR) databases.
6.2.2.4 Remote terminals
Regarding Globalstar remote terminals, there exist both, one-mode and two-mode terminals. The onemode
terminal operates only over the Globalstar system, and the two-mode terminal is able to operate
on both the Globalstar system and one terrestrial system. In Globalstar operation, terminals implement
a three-channel rake receiver so that they can receive signals from more than one satellite
simultaneously.
The basic remote terminal is a handheld unit, similar to a terrestrial cellular mobile phone (although
with a longer antenna).
6.2.3 ICO
6.2.3.1 System overview
ICO (which name comes from Intermediate Circular Orbit) is a Medium Earth Orbit (MEO) satellite
constellation that consists of 12 satellites (10 operational plus 2 spares) in 2 inclined orbit planes at an
altitude of 10,355 km above the earth‘s surface. It is in operation since 2000.
Initially, the ICO system was designed for a global mobile voice telephony services, structured around
the reuse of GSM technology for the ground infrastructure, since expected services were GSM-like
circuit switched services. However, this design was changed during satellite production phase in order
to provide both circuit and packet switched services.
Circuit switched services are:
- Voice at 4.8 kbps (basic voice)
- Enhanced voice service at variable rate
Doc.Nº: SRAIL-FNR-010-IND
Edit./Rev.: 1/1
Date: 16/02/2017
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