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StatusOngoing
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Status date2008-02-19
AMERHIS is an ALCATEL ESPACIO initiative, supported and co-funded by ESA and Industry, to deploy an advanced communications system based on a regenerative payload on board the AMAZONAS satellite.
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In this system, the DVB-RCS return channel standard is applied by all users to access through a standard uplink to the satellite. On-board, the regenerative payload is in charge of multiplexing that information from diverse sources into one or more DVB-S data streams capable of being received by any standard IRD equipment. The on-board repeater is not only capable of multiplexing signals coming from the same uplink, but also cross-connecting and/or broadcasting channels coming from separate uplink coverage areas to different downlink coverage areas.
A Management Station is needed to perform management functions for the integrated system. It also can directly transmit to the satellite the signalling and timing information for network operation by using the same DVB-RCS standard and receiving the different return channels
Uplink:
Format: MF-TDMA according to DVB-RCS standard (MPEG-2 option)
Granularity: up 64 carriers per transponder (0,5 Mbps each)
Available Data rates: 0.5, 1, 2, 4 & 8 Mbps, combinable in the same transponder
Coding Scheme: Turbo Code with 3/4 or 4/5 ratio
Figure 4 (click for larger image)
Downlink:
Format: according to DVB-S standard
Data rate: 54Mbps (per transponder)
FEC: Convolutional coding with 1/2, 2/3, 3/4, 5/6 or 7/8 ratio
On-Board Operability:
Interconnectivity: full routing flexibility between input/output transponders
Capacity Management: Two modes of operation possible
- Quasi-static through telecommand channel (via TTC station)
- Dynamic through communication channel (via NCC)
On-Board Budgets (4 channels):
Total Processed Capacity: 216Mbps
Power Consumption: 210W (52.5W per channel)
Mass: 29.5Kg (7.4Kg per channel)
Figure 5 (click for larger image)
Multimedia Services and Applications:
Amerhis foresees Internet/Intranet access, IP multicast, LAN interconnection, audio/video and video broadcast services. These services support a great variety of applications. Some of them are: Interactive and non interactive Teleservices, Distributed Interactive TV, Video broadcast/on demand, Radio/news broadcast/on demand, Web browsing / news group / e-mail, File transfer Telemedicine / Teleteaching, Videoconference / Audioconference, Teleshopping / Telebanking,- Interactive Gaming, Collaborative work,
The combination of On-Board Processing and a full compatibility with the open standards DVB-S (downlink) and DVB-RCS (uplink) gives to the telecommunications satellite an unprecedented potential ahead of conventional bent-pipe architectures.
Among the most relevant advantages provided by the OBP are:
Provision of direct mesh end-to-end connectivity between any two users or star connectivity between users and a gateway, through a single satellite hop, this allowing real time voice and video services as well as reduced bandwidth use.
The simplification of the Ground Segment, the system not requiring hub stations for providing the user access interface and traffic management.
Full flexibility for the interconnection of coverages as well as for the payload capacity management, this allowing the optimisation of the available on-board resources.
All this, together with the use of standard user terminals of low cost and high performances (interactivity and broadband), will make a qualitative step in the commercialisation of interactive multimedia services via satellite.
Figure 6 (click for larger image)
The complete AMERHIS System is divided in two segments:
Space Segment:
OBP: Down Converters (DOCON), Base-Band Processor (BBP) and Ku Modulators.Ground Segment:
Management Station (NCC, NCC-RCST, NMS). Gateway.
Different types of Return Channel Satellite Terminals (RCST).
Figure 2 (click for larger image)
The heart of the system will consist of 4 fully interconnected channels (33MHz each) that will be inserted in the AMAZONAS Ku Band Transparent architecture. The On-Board Processed (OBP) payload will be by-passable on a channel-by-channel basis.
Figure 3 (click for larger image)
The following items were developed in the frame of the AMERHIS project:
On Board Processor BreadBoard (2002): It consisted of one functional channel but with two channels at Base Band level, for cross connection testing, between different channels.
One Test Bench (2003): In order to qualify the EQM and to perform the acceptance test of the FM. The core of this Test Bench was mainly developed under DOMINO2 contract.
One EGSE (2003): It allowed integrating the OBP within the rest of the payload and was based on the Test Bench. It was operated at ASTRIUM premises by ALCATEL ESPACIO experts, it returned to ALCATEL ESPACIO when on-board hardware was integrated.
On Board Processor EQM (2003): It consisted of one end-to-end channel but with two channels at Base Band level (BBP developed under DOMINO 2 contract). It was thermally and mechanically representative of the final Flight Model.
On Board Processor FM (2003): It consisted of four end-to-end channels.
Test Beds to perform the AMERHIS System validation and pre-launch and in-orbit acceptances. The AMSVT (2003), the AMERHIS Multimedia System Validation Test, shall be derived from the one developed by ASP for the CNES and will allow the in factory validation of the AMERHIS Validation System (breadboards based). The AOSVT (2004), AMERHIS Operational System Validation Test, will allow for the final validation of the AMERHIS System delivered to HISPASAT.
RCST's (2004): A total of 22 complete RCST's (including both IDU + ODU) plus additional 8 IDU's are right now foreseen.
Two GATEWAYS (2004).
The MANAGEMENT STATION (2004), that will consist of: NCC, NCC-RCST and NMS.
The AmerHis Payload was embarked on board the Amazonas satellite, which was launched on August 2004. Then after In orbit tests were sucessfully performed, Alcatel Alenia Space España formally delivered to ESA a Pre-operational Validation Pilot. The AmerHis System was accepted by ESA, who appreciated the quality of the work done along all the project phases.
The close out of the project meeting took place at the Alcatel Alenia Space España prime contractor premises located in Tres Cantos-Madrid (Spain) on the 13th and 14th of July, 2006, with the participation of the ESA, Hispasat and Alcatel Alenia Space representatives.
From that date on the system was put in the hands of Hispasat for its commercial exploitation.
Since the delivery of the system many enhancements have been analized and introduced as route definition enhancement for Low cost terminals or NCC routes support at C3.
To date the system has demonstrated a good reliability and excellent capabilities during the many demonstrations and its live application to different projects, i.e:
- Support to ESRIN for DDS over Amerhis,
- Telemedicine over AmerHis,
- Participation in Spanish and European CWID, with tests on both clear and crypto scenarios.