Solutions for Satellite IP Data Transmission - Satcom Services

Solutions for Satellite IP Data Transmission 

1.0 Overview 

Advantech, with many years of experience in providing IP (Internet Protocol) 

connectivity via satellite systems, offers solutions tailored for many different 

applications. Advantech’s solutions have been designed to support networks 

scaling from single point-to-point links up to networks requiring 10,000+ users. 

More significantly, we have many customers using these systems every day, 

carrying data vital to their business. 

Our systems start from simple IP Bridges, that can be optionally fitted to all of our 

standard SCPC products, progress to satellite networking products, including 

DVB-S2, DVB-SCPC and DVB-RCS solutions culminating to IP networks for 

thousands of users and dedicated high speed >100Mbps point-to-point IP data 

links. 

2.0 Applications 

As many communication applications begin to use it as a basis, IP support is 

becoming increasingly important to the world of satellite communications. For 

example: 

• IP multicasting 

• Fast Internet access, e.g. Internet cafe 

• Voice over IP telephony (typically as part of an Internet access package) 

• Proxy server synchronization 

• Streaming Audio/Video 

• Business TV, Training, Live Events 

• Push: Stock Market, News Feed and Database 

• VPN with centralised databases 

There are many markets in need of such solutions yet in our experience, the 

most common are: 

• Extending corporate network access to remote sites. 

• Internet provision to remote sites. 

• Defence applications (e.g. Internet café for troops). 

• Multimedia broadcast and contribution links. 

www.satcom-services.com 

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Satellite communications equipment is now completely network-aware and 

provides a full network stack above the transmission layer. Advantech has 

acknowledged this and offers diverse network capabilities in its product portfolio. 

An IP-based satellite network can be seen as an IP network cloud. In a typical 

star configuration, the network consists of access terminals and a satellite 

gateway or hub. The IP capabilities of the satellite modem can vary depending 

on the site requirements. For access terminals, the set of IP features offered by 

Advantech include: 

• DHCP 

• NAT/PAT 

• VLAN 

In addition to these standard access features, Advantech IP networks offer 

industry-leading capabilities including: 

• TCP and HTTP Acceleration 

• Level 3 QoS 

• Encryption 

• Firewall/Packet Filtering 

• Static and Dynamic Routing 

• AAA (Authentication, Authorization and Accounting) 

• IP Services including DNS and FTP/TFTP 

Advantech IP products are entirely SNMP manageable and offer additional 

configuration interfaces including CISCO TM -like command line interfaces and 

HTTP graphical management. 

The complete list of IP features are described in the IP Gateway data sheet, 

which is available from the by contacting us: Joyce@satcom-services.com 

Advantech satellite IP networks can be classified in three families: 

• DVB-based two-way satellite networks (with SCPC or RCS return links) 

[Section Error! Reference source not found.3.0] 

• SCPC Star networks [Section 4.0] 

• High speed backbone / high speed distribution links [Section 6.0] 


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The selection of one of these networks is based on service-provider 

requirements including the IP services, network size and integration with existing 

networks. The selection criteria are described in more detail in Section 5.0. 

DVB-based two-way satellite networks (SatNet) support a service-provider’s 

network requirements at all stages of network deployment, offering low initial 

investment that subsequently grows in-line with network expansion. Starting from 

small-scale SCPC networks, the network evolves to a DVB-RCS MF-TDMA 

network. The key aspect of this approach, known as SatNet Pay-as-You-Grow TM , 

is the re-use of user terminal equipment in both SCPC and RCS. This offers the 

service-provider major cost savings as their network size grows. 

The DVB-SCPC and DVB-RCS SatNet solutions rely on the DVB standards on 

both the forward and return links and offers an integration path with existing 

service-provider infrastructure. 

The SCPC Star network solutions are based on the AMT60 product and offer 

increased bandwidth efficiency through the use of HDLC framing on the satellite 

link. Well-suited to dedicated high quality links that require fixed bandwidth, the 

SCPC Star network can also operate with a star topology DVB forward link for 

integration in existing MPEG multiplexers. 


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3.0 Advantech SatNet Solutions (DVB-SCPC & DVB-RCS) 

Advantech offers the most scalable solutions of the industry available at the most 

competitive cost. The SatNet Pay-as-You-Grow approach supports the service 

provider's requirements at all stages of a network deployment. Starting from an 

SCPC-based network, our strategy enables the network operator and service 

provider to migrate to DVB-RCS while re-using the same user terminal 

equipment and forward link equipment. This allows to easily grow the system 

from a few SCPC terminals to hundreds of DVB-RCS terminals. Further, the 

Pay-as-You-Grow strategy makes it possible to scale up the DVB-RCS hub 

from hundreds of terminals to tens of thousands of terminals. 

3.1. DVB-SCPC 

The DVB-SCPC SatNet solution combines a high rate forward link with a set of 

discrete return link carriers providing dedicated bandwidth to each of the user 

terminals. DVB-SCPC networks offer the advantages of being easily installed 


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TALK / DATA 

TALK 

RS CS TR RD TD CD 

TALK / DATA 

TALK 

RS CS TR RD TD CD 

and have lower operational costs, particularly at initial network deployment. The 

hard committed bandwidth of SCPC is also attractive to many users of SCPC 

networks. 

The DVB-SCPC network architecture is shown in below: 

IP Encapsulator 

AMT-70 

AMT-34 

1:N 

Splitter 

S5400 

S5400 

Customer 

LAN 

Customer 

LAN 

Optional 

Router 

AMT-34 

HUB 

TERMINALS 

Figure 1: DVB-SCPC Network Architecture 

Forward Link 

The forward link is based on the DVB-S/S2 standard (EN 300 421/ EN 302 307) 

used for digital video broadcasting. The forward link carrier rate can vary from 1- 

45MBaud with data rates of up to 80Mbps (limited by terminal throughput). 

The forward link uses Multi-Protocol Encapsulation (MPE) of IP data into MPEG 

frames. An Advantech encapsulator is used in the Gateway for data 

encapsulation; however, this architecture is suited to introduction of 3 rd party 

encapsulators. 

Return Link 

The return link is an MPEG-based SCPC carrier that utilizes the coding available 

in DVB-RCS. To maximize return link bandwidth efficiency, section packing is 

used in conjunction with MPE. 

The return link supports both QPSK and 8PSK modulation. 


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DVB-SCPC Micro Hub 

The DVB-SCPC Micro Hub is an IF (L-band or 70/140 MHz) - Ethernet integrated 

modem-router equipment chain that provides access to the terrestrial network. 

The hub consists of a single broadcast forward transmit chain in conjunction with 

return links comprising of banks of SCPC receivers. Both the broadcast forward 

link and SCPC return receivers have Ethernet interfaces and therefore can be 

configured to suit the network infrastructure of the hub. All that is required is to 

close the IP loop in the regular switch/hub device. 

AMT34: 4-Channel SCPC Integrated Receiver Router 

The AMT34 can be configured as a quad receiver for the scalable architecture. 

When configured for this architecture, the AMT34 includes the IP Gateway, 

MPEG to IP de-capsulation and offers a native 10/100BT Ethernet interface. The 

AMT34 can be easily integrated into the gateway IP infrastructure as required by 

the end-customer. 

IP Encapsulator 

The SCPC Encapsulator is an Ethernet to ASI IP Encapsulator. This 

encapsulator performs standard MPE encapsulation of IP and interfaces to the 

modulator via ASI. Advantech provides an extremely cost-effective IPE solution 

for this application. Additionally, 3 rd party encapsulators may also be used for 

meeting specific customer requirements. 

AMT70 Modulator 

The AMT70/75 DVB-S/S2 modulator is configured with an ASI interface for 

connection to the IP Encapsulator. 

3.2. DVB-RCS 

In its standard form, a DVB-RCS network is a star-based VSAT network 

providing access to the Internet and related networks. Advantech offers a 

compact RCS system that supports up to thousands of user terminals, and 

beyond, in this architecture. In addition, the capabilities of this network go 

beyond standard RCS to offer 8PSK return links and mesh capabilities, DVB-S2 

ACM, as well as dual SCPC/RCS return link capabilities. 


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Forward Link 

The forward link is based on the DVB-S/S2 standard (EN 300 421/ EN 302 307) 

used for digital video broadcasting. The forward link carrier rate can vary from 1- 

45MBaud (DVB-S) with data rates of up to 80Mbps. 

The forward link uses Multi-Protocol Encapsulation (MPE) of IP data into MPEG 

frames. As with the DVB-SCPC network, an Advantech-provided encapsulator is 

available and the architecture supports 3 rd party encapsulators. 

Return Link 

The return link is Multi-Frequency TDMA. Each TDMA carrier can range from 

64kbps to 8Mbps. The terminal is capable of frequency hopping among the 

return link carriers to ensure maximum use of return link bandwidth. A hub-based 

scheduler provides dynamic bandwidth control. 

The transmission by terminals on the return link is controlled via the hub – only 

logon burst use random access. Individual terminals can be assigned constant 

bandwidth or the terminal can make dynamic bandwidth requests. These two 

mechanisms can be combined to guarantee each terminal a minimum bandwidth 

while allowing access to a complete return link carrier bandwidth for short 

periods. 

The inbound return links support concatenated RS/Convolutional or Turbo 

Convolutional encoding, using QPSK modulation and with an option for 8PSK 

available. 

Return link bandwidth is assigned to user terminals in a Burst Time Plan. The 

bandwidth scheduling algorithms support Committed Information Rate (CIR) and 

dynamic packet-by-packet bandwidth requests. This provides an exceedingly 

flexible mechanism for scheduling individual terminals in regards to Service 

Layer Agreements (SLAs). 

DVB-RCS Micro, Mini & Max Hubs 

The DVB-RCS Hub product portfolio consists of equipment-scalable rack units 

that operate both as a DVB-RCS modem and as a network manager providing 

access to the DVB-RCS network. The product line consists of the Micro, Mini 

and Max hubs, capable of supporting networks as small as 20 terminals and as 

large as 10,000 terminals, and beyond. 


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Management 

Ethernet 

Traffic 

Ethernet 

Network Manager 

Router 

Encapsulator 

10MHz 

1pps 

ASI 

Ethernet 

AMT-70 

Modulator 

with NCR 

Burst 

Demodulator 

Figure 2: DVB-RCS Hub Schematic 

AMT70 Modulator 

The hub uses the Advantech AMT70 Universal Modem. The AMT70 supports a 

broad range of transmission standards including both DVB-S and DVB-S2. As 

part of RCS network synchronization, the AMT70 supports NCR time stamping 

and synchronization via 10MHz and GPS’ 1pps inputs. 

The AMT70 supports the full range of DVB-S/S2 coding and modulation. 

Burst Demodulator 

The hub burst demodulator is a full IF to baseband multi-carrier demodulator 

(MCD). Packaged as a single rack-mount unit, the MCD supports an L-band 

interface, performs frequency de-multiplexing, burst demodulation and decoding 

and IP reassembly. 

Features of the MCD include: 

• L-band interface (950 to 2150 MHz). 

• Maximum Throughput: 24Mbps 

• Maximum Bandwidth: 34MHz 

• Supported Traffic Encapsulation Format: 1 & 2 ATM and MPEG 


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• Symbol Rate: Selectable per carrier 

• Burst Format: Selectable per carrier 

• Maximum number of carriers per MCD: 96 

• Carrier rates: 64kbps to 8Mbps 

• Channel spacing: 1.25 to 1.50 (variable) 

• QPSK and 8PSK demodulation. 

• Timing, Power and Frequency Measurements on a burst-by-burst basis. 

• Turbo or RS-V FEC decoder. 

• 10MHz/1pps synchronization including NCR loading. 

Network Manager/Router/Encapsulator 

The main features are: 

• Network Manager 

♦ Network entry and exit control 

♦ Return link bandwidth scheduling 

♦ Configuring the return link 

♦ Monitoring the performance of terminals on the return link 

♦ Monitoring overall network performance 

• Router 

♦ Forwarding of IP traffic between the satellite and terrestrial networks 

♦ IP-Layer traffic shaping (using an optional traffic shaper) 

♦ Level 3 QoS 

♦ Terrestrial Routing Protocols 

• Encapsulator 

♦ MPE encapsulation of user IP traffic 

♦ Insertion of RCS tables 

♦ Support for 3 rd Party encapsulators 

3.3. DVB-SCPC/RCS Terminals 

Advantech offers a portfolio of terminal products for the DVB-based two-way 

SatNet solutions. These terminals are built on field-proven DVB-RCS technology 

that has been deployed worldwide. Advantech Satnet terminals are DVB-RCS 

standard compliant and offer additional value-added features that enable the 

service-provider to increase their return on investment. Key features of the 

terminal portfolio include: 

• Full-featured IP networking including QoS 


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• DVB-S and S2 Forward Links 

• SCPC and DVB-RCS Return Links 

• High Forward Link Throughput (36Mbps sustained) 

• High Return Link Throughput (up to 8Mbps) 

• Higher Order Return Link Modulation (8PSK) 

• Local and remote management via SNMP, HTTP and Command Line 

Interface 

• Installation support including scripts and antenna alignment tools 

• Reliable remote software upgrade 

• Flexible multicasting 

• Industry standard BUC/LNB Interface with 2-cable IFL 

The Advantech SatNet terminal portfolio consists an Indoor Unit (IDU) and 

Outdoor Unit (ODU). Two product lines are available: the affordable Series 4000 

(with Model S4100) and the enterprise-oriented Series 5000 (with Models 

S5100/5200/5300/5400). Both product lines support DVB-S and DVB-S2. The 

Series 5000 supports as well Mesh connectivity, DVB-S2 ACM mode, and SCPC 

transmission mode (for DVB-SCPC satellite networks). There is also a receiveonly 

terminal (ROT) supporting both DVB-S and DVB-S2 called based on the 

Model S1010 IDU. 

Figure 2: DVB-RCS Terminal Schematic 


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4.0 SCPC Star Network Solutions (AMT60/65) 

The AMT60/65 system provides an SCPC network combining a high rate forward 

link with a set of discrete return link carriers providing dedicated bandwidth to 

each of the user terminals. SCPC Networks offer the advantages of being easily 

installed and have lower operational costs, particularly at initial network 

deployment. The hard committed bandwidth of SCPC is also attractive to many 

users of SCPC networks. 

The AMT60 system can be scaled from QPSK to 16-ary constellations on both 

forward and return link while the return link can support up to 10Mbps sustained 

throughput. In addition, AMT60 systems can operate as either MPEG-TS MPE 

encapsulation, or HDLC (Frame Relay), consequently further improving 

spectrum efficiency. The SCPC network architecture is shown below: 

AMT-70 U/C PA 

Router 

Forward Link 

HUB 

AMT34 

IP G/W 

D/C 

LNB 

Return Link 

Frame Relay System 

RFFE 

AMT61 

Terminal 

RFFE 

AMT61 

Terminal 

RFFE 

AMT61 

Terminal 

RFFE 

AMT61 

Terminal 

Figure 3: Frame Relay based AMT60 series Solution 


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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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AMT61 Integrated Terminal (1RU 19inch Rack) 

10/100 

Base-T 

IP 

Gateway 

AMT30 

Modulator 

L Band 

Demodulator 

DVB-S/ DSNG/ S2/ Turbo 

Figure 4: AMT61/65 Terminal Architecture 

This architecture enables very powerful high-speed IP terminals with guaranteed 

latency and throughput. 


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4.3 AMT60/65 Forward link example with MPEG 

MPE AMT-70 U/C PA 

Router 

Forward Link 

HUB 

AMT34 

IP G/W 

D/C 

LNB 

Return Link 

RFFE 

AMT61 

Terminal 

RFFE 

AMT61 

Terminal 

RFFE 

AMT61 

Terminal 

RFFE 

AMT61 

Terminal 

Figure 5: AMT60 series with MPEG Framing 

It is also possible to use the AMT60 series in a system with MPEG 

encapsulation. The Hub for this system will be identical to the DVB-SCPC SatNet 

system. It requires an MPEG Encapsulator and the AMT34 units incorporate 


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MPEG de-capsulation. The terminals also implement MPEG Encapsulation / Decapsulation 

in their IP Gateway cards. 

This system could find application in a Hybrid network which shared a common 

DVB forward link but the terminals could either be DVB-RCS for lower bandwidth 

TDMA users or AMT61 for users who required an SCPC return link with its 

guaranteed bandwidth and latency. 


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5.0 IP Network Selection 

The selection between a DVB-SCPC networkand an AMT60 network is based on 

the services and the network size. This section focuses on the return link 

element of these systems as the differentiator. In terms of forward link, both 

systems support DVB-based links and can be integrated with existing 

infrastructure – the AMT60 also offers Frame Relay/HDLC framing that has 

reduced overhead when compared to DVB-MPE and support for 16QAM / 

16APSK forward links. The IP features are common between the two network 

types. 

Both DVB-SCPC and AMT60 operate in SCPC mode, providing dedicated 

bandwidth to end customers. SCPC is well suited to applications where the 

customer has a continuous bandwidth requirement or when a customer needs 

guaranteed access to a fixed amount of bandwidth. A service-provider who has 

these requirements with no plans to evolve the services can choose either DVB- 

SCPC or AMT60/65 based networks. On the other hand, the AMT60/65 offers 

the advantage of higher data rates (>110Mbps), lower bandwidth overhead with 

HDLC framing and higher order modulation schemes in both directions. Both 

DVB-SCPC and AMT60 solutions can be integrated with existing DVB-based 

forward links. 

Service-providers who foresee a migration to MF-TDMA can start with the DVB- 

SCPC solution and change to MF-TDMA when appropriate. The MF-TDMA DVB- 

RCS network can be operated in both contention-less and contention-based 

modes depending on how the service-provider configures the return link 

scheduler. As compared to SCPC services, which scale with number of users, 

the RCS hub infrastructure costs scales with either users or bandwidth. This 

means that for services that rely on statistical multiplexing, the infrastructure 

costs will be lower as the bandwidth is shared. 

The contention-less mode of operation, implemented through providing 

committed information rates, can offer reduced infrastructure and bandwidth 

costs as the service-provider network grows. Contention-based services are well 

suited to burst traffic requirements, which are typically related to HTTP and 

Internet access. 

In addition to the trade-offs that can be made based on these considerations, it is 

also possible to offer hybrid networks, simultaneously consisting of both SCPC 

and DVB-RCS links in order to optimise the offering of the service-provider. 


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6.0 High Speed Back-bone / Distribution Solutions 

The AMT75 product range offers high-end IP Back-bone and IP distribution 

solutions. The range is outlined in Error! Reference source not found.. AMT75 

is a wide-ranging (from 128kbps to 150Mbps) DVB-S2 QPSK, 8PSK, 16APSK 

and 32APSK product. It also supports multi-stream Variable Coding Modulation 

(VCM) and Adaptive Coding Modulation (ACM) operating modes. 

Table 1: AMT75 Configurations 

Model ASI 10/100 Base-T 

Ethernet 

Octal G703 

& 10/100 Base-T 

AMT75 Modulator √ √ √ 

AMT75 Modem √ √ √ 

AMT75R Receiver 

only 

√ √ X 

AMT75R Dual 

Receiver 

√ √ X 

The AMT75 can be configured to distribute IP from an AMT75 TX only modulator 

to multiple AMT75R receivers. Both the modulator and receiver have the IP 

encapsulation and de-capsulation functions integrated into the units along with 

full router capabilities. The system can be configured to have routing or just to be 

an Ethernet bridge. The in-built router can process up to 35,000 packets per 

second allowing up to 92Mbps of large packet IP to be transmitted over the 

satellite link. 

Alternatively 2 or more AMT75 can be deployed in point-to-point IP backbone 

applications for IP trunking applications. 

Applications for AMT75 include high speed > 50Mbps IP distribution to multiple 

receive sites, such as distributing IP TV to multiple triple-play head-ends. The IP 

backbone applications include IP backbone disaster recovery restoration, 

backbone solutions where fibre is not present and IP broadcasting of H.264 

video. 


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7.0 Glossary of Terms 

Table 2: Glossary 

DVB 

DVB-DSNG 

DVB-MPE 

DVB-RCS 

DVB-S 

Digital Video Broadcast, the Project defining transmission standards 

Digital Video Broadcast, Digital Satellite News Gathering 

Digital Video Broadcast, Multi-Protocol Encapsulation 

Digital Video Broadcast, Return Channel over Satellite 

Digital Video Broadcast, Satellite 

DVB-S2 Digital Video Broadcast, Satellite – Version 2 

HBD 

HDLC 

IP 

MF-TDMA 

MPEG 

SCPC 

Hub Burst Demodulator 

High-level Data Link Control 

Internet Protocol 

Multi Frequency – Time Division Multiple Access 

Moving Picture Experts Group, authors of encapsulation standards for multimedia data 

Single Channel Per Carrier 


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Solutions for Satellite IP Data Transmission - Satcom Services

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