Fraunhofer Institute for Integrated Circuits IIS
Fraunhofer Institute for Integrated Circuits IIS
Beam hopping
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Flexible Transmission Concept for High Throughput Satellite Systems

© sdecoret – stock.adobe.com / Bearbeitung Fraunhofer IIS

Beam Hopping

Utilizing satellite capacity in an efficient and demand-oriented way

Beam hopping is a concept that allows data transmission via satellite to be flexibly adapted to the variable data demand in any given area. Instead of statically supplying a specific area with data, the satellite switches back and forth between different coverage areas. The switching of the satellite beams is based on a schedule that takes into account the data rates currently required in the various coverage areas. Overall, the concept improves the efficiency of a satellite system because the transmission capacity is always available in full bandwidth exactly where it is needed at any particular moment.

A beam-hopping-capable system flexibly compensates for fluctuations in user demand and is designed to achieve the best possible overall utilization:

  • Adapts to the varying demand in the course of the day
  • Facilitates the adaptation of a satellite to new services with a different workload
  • Supports coverage for locally fluctuating data traffic from mobile users
Functionality beam hopping
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The challenges of a beam-hopping-capable system

The use of beam hopping techniques requires optimization and adaptation of classical modulation and demodulation methods as well as solutions for a reliable and demand-adapted control of the beam switching.

Exact synchronization

On the transmitter side, special scheduling algorithms are needed to optimize the resource allocation according to the data requirements of the users and in order to calculate adjusted beam hopping schedules. Especially in the case of transparent beam hopping satellites, smooth synchronization between the uplink transmission of the gateway and the beam switching at the satellite is crucial. If a satellite is equipped with an on-board processor (regenerative payload), scheduling takes place directly at the satellite, which better avoids incorrect beam/data assignments. Using a transparent or regenerative payload – in both cases, the challenge is to avoid sending data packets to the wrong beam, especially when the beam hopping schedule changes frequently.

Reliable signal processing at the receiver end

The bursty data transmission in the downlink requires special features on the receiver side for reliable processing of the discontinuous input data. For this purpose, among other things, the control of the amplification of the received signal must be robust against a strongly fluctuating receive power. In addition, exact synchronization with respect to time and frequency is required. The use and processing of a strong preamble sequence, as contained in the super-frame waveform of the DVB-S2X standard, can support this task.

 

 

Suitable test equipment

In the context of technology development for beam hopping systems, suitable test equipment is required with which terminals and transmission methods can be tested and optimized in a wide variety of beam hopping scenarios. Fraunhofer IIS has developed a beam hopping emulator for this purpose, which can be used to variably control beam switching:

  • Fine-granular definition of the beam hopping schedule (emulation of the on/off behavior is also possible)
  • Emulation of cross talk between "neighboring" beams
  • Adjustable signal-to-noise ratio (SNR) or definable noise from internal or external sources
  • Analog transparent signal path and thus without bandwidth limitation
  • Internal oscillator or external clock signal

Your development partner for the realization of beam-hopping-capable transmission systems

Consulting

We advise satellite operators and equipment manufacturers in the planning and conception phase on all questions of system layout and receiver design. For this purpose, we conduct comprehensive feasibility and concept studies.

Implementation

Within the scope of the realization of suitable terminals, we take care of the integration of beam hopping functionality on test platforms up to the customer-specific development and integration of IP cores for professional equipment.

Test and verification

Fraunhofer IIS has its own beam hopping test bed for performance and verification tests. With the associated beam hopping emulator, tests can be performed both in the lab and over-the-air.

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