AMT-70/AMT-73/AMT-75 Installation and Operation
unit supporting DVB-S, DVB-DSNG and DVB-S2 SHORT and NORMAL blocks. In this configuration,
the ASI input is used to receive MPEG-2 data for onward transmission. It is possible to include a
Demodulator in the same 1RU unit. This can be used to monitor the Modulator output and it outputs an
ASI stream.
There are two generally supplied configurations for this mode of operation – redundant and non-
redundant. Redundancy support may be provided without the need for an external controller.
3.3.2
Data Broadcast Modulator
Traditionally DVB modulators have been used in conjunction with MPEG-2 data encapsulators to
provide a high-speed data distribution forward link into a star-network. The return link is then typically
achieved using SCPC modulators such as the AdvantechAMT-10 or via terrestrial modems. The AMT-
70 can be operated in this mode if required: typically for these systems, taking input from ASI.
However, it is also possible to directly connect the Modulator to the output of an IP router using the
HSSI interface. The modulator can still operate in a DVB mode – the user selects the DVB FEC /
Modulation mode they desire and unframed data. The Modulator then inserts the required DVB sync
marks into the data stream and transmits it. At the remote station, the user has several solutions
available to receive the data stream including the AdvantechAMT SBR-70 single board receiver or third
party receivers.
TCP/IP data can be encapsulated in frame relay format in the Router. This mode of operation can save
significant money in the head-end, as DVB IP encapsulation is no longer required. The use of eTPC
can also significantly reduce the satellite bandwidth cost over the lifetime of the system. The AMT70
can also be order with an inbuilt IP router removing the need for expensive external data encapsulator
units.
3.3.3
SCPC Modem
AMT-70 supports traditional SCPC modem applications, offering a wide choice of data-rate from
64kbps to 52Mbps on the RS-530 and HSSI data ports and from 256 kbps to 140 Mbps on the ASI
data port. Current options include 10/100 Base-T Ethernet and Triple HSSI. Future options for the data
ports will include multiple E1, T1, E3, DS-3. Many features of the modem can be upgraded as required
in the field allowing the product capability to grow as your traffic and revenue increases.
3.3.4
Bandwidth-On-Demand Modem
The AMT-70 can be operated in a Bandwidth-On-Demand (BOD) mode with the appropriate network
software, and the use a separate control channel for setting up the link. This control channel could be
a separate channel over the satellite, a dial-up RS-232 or RS-485 modem, or the more popular Internet
whereby the 10/100BaseT M&C port is connected to a low-speed dial-up Ethernet modem or a high-
speed cable, DSL (digital subscriber line), or ISDN (integrated services digital network) line. The use
of a router in this latter choice allows other modems at that earth station location to be addressed from
a single Internet connection.
3.3.5
Broadcast Mode
The AMT-70 series modem is well equipped to operate in a broadcast mode whereby a single
outbound carrier can be transmitted to a series of receive sites. A companion demodulator, called our
SBR-70, installed at each of these receive sites, which have the same wideband data capability with
Viterbi and Viterbi Reed Solomon, can then be set to receive these broadcast signals in either the
DVB-S, DVB-DSNG, or Intelsat formats. Equipped with the optional eTPC turbo cards, the modulator
and demodulator can be used in a proprietary and powerful FEC algorithm.
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3.4
Default, Memory Store and Recall Modes
The modem incorporates a default option that sets the modem to a known set of known parameters
preset at the factory. Additionally the modem includes 10 memory store and recall modes that can be
preset by the customer for instant recall and activation, similar to that of a pushbutton radio.
Summary of Contents for AMT-70
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