26-04-2012, 11:09 AM
Paradise Datacom connecting GSM networks via Satellite
GSM.pdf (Size: 795.63 KB / Downloads: 91)
Introduction
The worldwide popularity of GSM has encouraged operators to deploy services
in most cities and, increasingly into remote areas. In parts of the world where
the terrestrial infrastructure is non-existent, GSM has enabled telecom services
for the first time. The only practical way to extend GSM services into these
remote locations has been via satellite.
For a GSM operator the task of designing and rolling out a new network is
considerable. The satellite link (or links) is only one consideration. Fortunately
GSM is inherently satellite friendly so the inclusion of the satellite link (or links)
is relatively simple. Satellite operators are providing an increasing amount of
applications support to the GSM operator, particularly with minimising the
space segment required for GSM traffic transmission. Satellite ground segment
equipment manufacturers are also providing increased functionality in their
equipment to best utilise bandwidth and minimise operating costs. Paradise
Datacom provides a one-stop shop for the system integrator or GSM operator
that needs ground segment equipment to connect via satellite. We have
designed compatible modem and RF products that make the task of integrating
a satellite link into a GSM network simple. Paradise Datacom designs and
manufactures the satcom equipment needed at both hub and remote sites. In
the following paragraphs we consider;
GSM Architecture and Satellite links
Figure 1 is a simplified version of a GSM network showing only the components
relevant to the transmission of voice and signalling information. For our
purposes, the GSM network can be viewed as consisting of three major parts:
the Mobile Switching Centre (MSC), the Base Station Controller (BSC) and the
Base Transceiver Station (BTS). The Home and Visitor Location Registers
(HLR and VLR) and other "back office" sub-systems are considered to be part
Evolution series modems (PD10, PD25 & PD55) with Quad E1 card
GSM systems often expand rapidly with an increased demand for more traffic
bandwidth on installed links to the point where the partial E1 (drop & insert)
delivery system becomes fully loaded, that is, a full E1 pipe. Additional traffic
bandwidth over satellite is historically provided by adding further E1 links over
satellite by means of adding more satellite modems. This is both expensive
(capital outlay for multiple modems) and time consuming, as new modem
hardware must be purchased, shipped, installed and commissioned.
of the MSC since these links would not normally be routed via satellite
Summary
Paradise Datacom satellite modems and BUCs are ideally suited for GSM over
satellite systems. Increased bandwidth (space segment) efficiency and better
system functionality are the key benefits of using these products for GSM over
satellite links.