The Spacelink^NGT Multi-Mission High-Rate Satellite Modem is one of the flagship products in the SpacelinkNGT range of Modem & TM/TC equipment of Satellite Services B.V. in The Netherlands. The ERSDEM-2.5 was specifically designed in response to market demand for affordable yet High-performance and Multi-Satellite High-Rate Modems and associated Ingest/ Level-0 processing equipment.

The ERSDEM-2.5 incorporates the latest System-On-a-Programmable-Chip (SOPC) technology and is based on fully digital (de)modulation techniques and proven algorithms. The demodulator & test modulator operate on a programmable IF span from 700 to 750 MHz and supports bit rates from 6 Mbps – 320 Mbps1 in several BPSK and (O/S)QPSK modes.

One of the unique characteristics of the ERSDEM-2.5 is the Single-Board implementation. Due to this, a single (VME form-factor) module operates as a standalone Demodulator or Test Modulator. This includes remote control/status and configuration via on-board Ethernet TCP/IP.

The demodulator can be combined with a Test Modulator, which can be used for short- and long-loop tests as well as system diagnostics and pre-pass testing. The Test Modulator includes a built-in Noise Generator, BER tester, PBRS pattern generator as well as a programmable Doppler & Sweep generator. The coding, modulation and satellite configurations match those of the demodulator.

Both the Demodulator and Test Modulator feature two physical (SMA) IF inputs/outputs. The active input for the demodulator can be selected through software. For the Test Modulator both outputs are active at the same time. The IF can be tuned from 700-750 MHz.

A variety of baseband inputs and outputs are supported. Standard interfaces include Differential-ECL and LVDS (customer specific adaptations possible). The modem supports I/Q merged or unmerged inputs/outputs and selectable data swapping/inversion as well as clock edges that can be selected for each interface individually.

Currently supported modulation schemes include: BPSK, QPSK, OQPSK, UOQPSK and AQPSK. The CCSDS 4D-GMSK modulation is expected to be available as from Q2/2006 as an additional in-the-field firmware/license update. Supported data coding formats include: NRZ-L, NRZ-M, NRZ-S and SPL with an optional VITERBI decoder (up to 110 Mbps). A differential encoder/decoder is included for ambiguity resolving in Q-PSK mode.

Set-up, Control and Status monitoring of each module is performed through an industry standard 10/100Base-T Ethernet interface. This supports a TELNET-like command/status interface and includes an HTTP / FTP server with on-line information, documentation and built-in support for firmware updates and new satellite configuration files.

Complimentary software provided with the standalone units include a easy-to-use remote GUI for System Control & Status and a real-time Scatter diagram.

1 Bitrates above 320 Mbps (up to 450 Mbps) can be supported on special tuned units, please consult Satellite Services B.V. for further information

Modular implementation

The ERSDEM-2.5 is implemented in a modular way. Each of the main functions of the unit, including the power supplies, are implemented as single plug-in modules. This allows a modular configuration of the unit in accordance with the customer or system requirements.

At present the following ERSDEM-2.5 single-board modules are available: (not including other baseband / up-down conversion. See further for details)

• ERSDEM-2.5 High-Speed Demodulator

• ERSDEM-2.5 High-Speed Test Modulator

• External Interface Module
(offering ECL/LVDS I/O from selectable interfaces including level conversion to/from ECL)

• ERSDEM-2.5 High-Rate Interface Module
(offering serial/parallel LVDS I/O and mapping on single-cable Gbit serial interface to SSBV baseband equipment)

From an integration / mechanical point of view, different off-the-shelf models of the ERSDEM-2.5 are currently available:

• ERSDEM-2.5 DT (4U/19”)
Offers a Demodulator, Test Modulator and EIM into a single 4U/19” rack mountable housing.

• ERSDEM-2.5i (4U/19”)
Offers a Demodulator, Test Modulator, EIM and provisions for
direct SSBV baseband hardware interfacing.
(incl. LED info on front-panel)

• ERSDEM-2.5 Di (3U/19”)
Offers a Demodulator and LVDS interface to SSBV Raw Data
Ingestion equipment that is delivered integrated with the unit. This includes LED and LCD front-panel information and Raw Data In- gestion software on the baseband platform.
(upgradeable to Level-0 Processor or custom processing)

• ERSDEM-2.5 TS (3U/19”)
Offers a Test Modulator and LVDS interface to SSBV Raw Data Simulation / Serialisation equipment that is delivered with the unit. This includes LED and LCD front-panel information and Data
Simulation software on the baseband platform.
(upgradeable to Level-0 simulator/encoder)

Since all modules (including power-supplies) can simply be removed from the back of the unit, in-the-field maintenance can be easily undertaken and the unit can easily be reconfigured. Alternative system configurations, such as dual-demodulation chains can also be accommodated.

Integration with other products

The unit can be used stand-alone as well as integrated with other Satellite Services B.V. products for High-rate baseband TM processing and simulation. (As readily supported with the ERSDEM-2.5 Di & TS.) For extension of the input/output frequency range IF converters and X/S-band up/down converters are also available from the SpacelinkNGT product range.

The ERSDEM-2.5i/Di are special versions of the unit that feature direct integration with Satellite Services B.V. High-Speed Telemetry baseband equipment via LVDS and/or Gbit serial links. With these versions of the unit; the baseband hardware/software status can be read directly from the ERSDEM-2.5i front-panel (LED/LCD). The complete baseband equipment and modem are operated from the supplied application software that complements the hardware to compose a high-speed multi-satellite Telemetry Processing and Simulation system capable of real-time Raw Data Ingestion, (CCSDS/ESA) Level-0 processing, data ingestion/archiving and LAN data distribution.

The baseband hardware is composed of a plug-in card from Satellite Services B.V. which is integrated into a commercial server platform that also runs the application level software. This hardware features SOPC technology to accommodate a variety of TM processing and simulation functions and standards and furthermore supports the accurate tagging of TM data with a time code (IRIG-B) and the Product Confidence Data as provided by the ERSDEM-2.5 demodulator.

TM acquisition is either controlled through locally entered downlink acquisitions (GUI) or autonomously (unassisted) through ASCII and /or XML formatted acquisition directives. Processed data can either be archived on the unit itself or be streamed to archiving media or LAN (10/100/Gigabit Ethernet) via NFS, FTP or other industry standard protocols.

An easy to use Graphical User Interface provides overall control and status monitoring of all hardware/software elements integrated into the system including support tools for archiving, PCD inspection, archive data exploring and scatter plotting.

A special multi-channel implementation is available which supports multi-link demodulator operation including in-system diagnostics, pre-pass self-test and automatic faulty chain take-over during operation. (Please, consult SSBV for more information.)

ERSDEM Remote Control & Monitoring Software (CMS)

To simply integrate and operate the ERSDEM, each unit is provided with remote control software (Windows/ Linux) that can be run on a standard PC with a LAN connection to the unit. All settings and real-time status of the Demodulator, Test Modulator and External Interface Module can be controlled and monitored by means of this software. A real-time demodulator scatter diagram application is also included. From the CMS basic scripts can be created and executed to allow single-click unit configuration.

X / S-Band interfacing

There are a number of 1U/19” up/down converter products available in the SpacelinkNGT product range. These products have been specifically designed to be implemented to work complimentary to the ERSDEM-2.5 modems. It is then possible to extend the ERSDEM IF range to S-Band (1.9-2.3 or 2.3 -2.9 GHz) and X-Band (8.0-8.5 GHz). Please take note of the separate datasheets for more information.