The Fraunhofer IIS Baseband System is one of the key components in the WorldSpace Processed Feederlink Station (PFLS) chain. It performs all of the necessary processing of service components generated by a broadcaster for uplink transmission in the WorldSpace digital network. These services can be analog or digital audio as well as data services.
The Baseband System processes the service components according to the WorldSpace digital format: MPEG 2.5 layer-3 audio encoding, broadcast channel multiplexing, demultiplexing and modulation onto the carriers which are then transmitted to the satellite.
Modular Solution
The PFLS can be adapted to the requirements of the service provider. Configurations for studio and uplink terminal at the same location as well as studio and uplink terminal at different sites are possible. Various interface standards are supported. To allow this flexibility, studio and uplink terminal can be customized from a small set of modules:
- Chassis with power-supply
- Baseband Board
- MPEG layer-3 audio encoder
- Digital Interface Board
- Modulator
- Embedded System Controller
- Chassis Bridge
This set of modules allows a station to be tailored exactly to the needs of a broadcaster: from a single-thread, collocated P1 station up to a "mini hub" with 32 Prime Rate Channels shared by several broadcasters.
Each chassis has space for up to 21 modules and includes a cable duct. A fully redundant station with 8 prime rate channels can be built using only 7 height units of valuable 19" rack space.
Expanding a station to more broadcast channels and a higher data rate can be done in many cases without downtime: simply by adding new modules and performing a reconfiguration via the Monitor & Control System.
Cost Effective Redundancy Concept
The Fraunhofer IIS Baseband System is plug&play: its Embedded System Controller will automatically detect the configuration of the chassis.
No hardware settings have to be performed on the modules by the service personnel. All cabling except the AC supply to the Baseband System goes to the front panels. The modules are truly hot pluggable and can be inserted into the chassis while the station remains fully operating. The "Embedded System Controller" will scan for the new configuration automatically and inform the user via the Monitor & Control Software. Every module indicates its present status at the front panel using LEDs of different colors.
In the case of future software changes and enhancements, almost every piece of soft- and firmware in the Basband System can be downloaded and controlled from a remote location.
If necessary, this allows the Fraunhofer IIS experts in Erlangen, Germany, to assist local service personnel in much shorter time than it would take to travel to the earth station.
A PFLS also needs a tool for verification and monitoring. Fraunhofer IIS has developed a measurement tool, the FLS-Tester. The FLS-Tester allows to verify the operation of the Baseband System. For example, the FLS-Tester can convert an output signal back to audio. This function is especially valuable, if the respective satellite downlink beam cannot be received at the location of the uplink station.
Easy Maintenance
The Fraunhofer IIS Baseband System´s modular and bus-oriented concept allows for true 1:n redundancy in all modules. This means, redundancy is not achieved by keeping a second, fully equipped Baseband System in stand-by, but simply by adding the spare modules into the chassis. No shelf spares are required. This also allows very cost-effective solutions for fully redundant small stations.
The modules can be placed in the chassis at the same cost as shelf-spares and become automatically active in case of a failure: no need for service personnel to rush and repair the station just in time. Also the power supply units can be made redundant with AC power from two different sources. If a broadcaster decides to start with a single-thread system, a later upgrade to a fully redundant installation can be done simply by adding the required modules to the existing chassis.
Open to Future Extensions
In the future, new types of services might be introduced into the WorldSpace System. Therefore the Fraunhofer IIS Baseband System´s flexible bus and interface concept allows adding new types of modules to the existing stations without changes.
Quality And Long Design Life
The owner of a Fraunhofer IIS Baseband System must have assurance that his product can be supported for many years. Therefore, the Fraunhofer IIS Baseband System design is based on proven industry standard components with a long product life cycle and not on short living consumer market components. All modules of the Baseband System are manufactured by ISO 9000 qualified suppliers.
State-of-the art tests performed ensure that only fully tested equipment is shipped out to the customers. Programmed serial numbers that can be read via the Embedded System Controller allow tracking of every unit and the recording of its history.
The Fraunhofer Institute IIS
For many years the scientists and engineers at the Fraunhofer IIS in Erlangen gathered experience in research, development and system design of digital broadcasting systems.
More than 250 engineers are covering wide areas of communication technology and IC design. Fraunhofer IIS has played an important role in the development of the WorldSpace System almost from the beginning and is one of the world leaders in audio coding technology. For the PFLS Baseband System, Fraunhofer IIS has teamed up with:
Globecomm Systems Inc. (GSI)
45 Oser Avenue
Hauppauge, N.Y.
GSI is offering customers the RF components as well as turnkey installation of WorldSpace Processed Feederlink Station.
