Solutions for Satellite IP Data Transmission - Satcom Services

4.1 Hub System
The hub for this system does not require an MPEG Encapsulation unit. This
saves both money and link capacity, as MPEG Encapsulation typically adds
approximately 16% to 20% overhead on top of the data. This function is replaced
by HDLC (Frame Relay) encapsulation inside the AMT70 Modulator. The
Modulator is equipped with a high speed (full 10/100 Base-T) IP Gateway card
and the HDLC encapsulation is implemented on this card. The Modulator can
transmit any of the supported AMT70 series modulation / coding systems
(Intelsat / DVB-S / DVB-DSNG / Turbo (eTPC) or DVB-S2 LDPC/BCH). This
would allow a Turbo 16QAM or 16APSK DVB-S2 forward link. The DVB-S2
forward link operates in Generic stream mode, which treats the forward link as a
pure serial data stream.
The return path reception in the hub is very similar to the DVB-SCPC and DVB-
RCS satellite networking systems. It is implemented using AMT34 Quad
Demodulator units including the IP Gateway card. However, in this system there
is no need for an MPEG De-capsulation function in the return path. This function
is replaced by an HDLC De-framer. Each of the Quad units has only one 10/100
Base-T output and aggregates the received data from 4 different remote
terminals into one IP data flow. Note that it is possible to construct VLANs within
the AMT60 system allowing different IP networks to use the common
transmission network without compromising each users network security.
4.2 AMT60/65 Series Terminal products
The AMT60 series supports a number of different terminals. The AMT60 is a
receive-only high-end IDR solution for users who utilize an alternative return path
technology. The receiver can support DVB-S / DVB-DSNG (8PSK/16QAM) /
Intelsat and Turbo (QPSK/8PSK and 16QAM) modes and can operate from
64kbps/S up to >100 Mbps/S.
The AMT61 sister product provides both receive and transmit functionality. The
receiver is identical to the AMT60 and the transmitter is based on Advantech’s
AMT30 series product and provides QPSK/8PSK/16QAM modulation with
Intelsat and Turbo encoding. The AMT65 is similar to the AMT61 but offers DVB-
S2 receive functionality. All these products are 1RU 19inch Rack Mount units
with a built-in IP Gateway and HDLC encapsulation / de-capsulation.
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Created on 12/12/2006 18:24:00 Issue 56