PAGE CONTENTS
Objectives
The objective of the Romantica ESA study activity is to develop Radio Resource Management (RRM) techniques for the new generation of commercial Very High Throughput Systems (VHTS).
These RRM solutions are capable of exploiting the functionalities of these new satellites systems based on active antennas and on-board processors in order to maximize the system throughput, while maintaining good Quality of Service (QoS) for all the interactive applications of a satellite telecommunication system (i.e. video streaming, web, ftp and VoIP traffic sources).
Challenges
The main challenge of the program is to research innovative RRM solutions able to follow in real time the fluctuations of traffic, while considering some typical traffic models, not uniform traffic maps and different classes of user terminals.
A critical task is the definition of a fast solution able to optimize the beam hopping plan and to continuously readapt it in line with the changes of the traffic requirements.
Another challenging task is the investigation about a modern packet scheduler algorithm, able to select the packets considering their traffic QoS requirements, and integrate it in the final RRM solution.
System Architecture
The RRM demonstrator includes two RRM algorithms:
- an Advanced RRM solution, that optimizes at the same time the system resource planning and the packet scheduling management.
- a Benchmark RRM solution, that optimizes only the packet scheduler
The general scheduler architecture of the Advanced RRM algorithm is presented in the next figure.
These main logical blocks are presents:
- The “traffic flow generator” that generates IP packets
- The “queue updater” manager that controls the queue status, filtering the overall packets generated by the previous logical block and selecting only the packet present in the queues for each illumination plan loop.
- The “Proportional Fairness Exponential Rule” (PF-ER) module, that deals with QoS requirements for the different traffic flows and in particular the QoS-class-based deadlines of the packets.
- The “TM-PPD” algorithm, that is able to optimize the illumination plan and to calculate the offered, usable and unmet capacity
- The “Final Scheduler”, that performs the second level of packet scheduling and identifies which packets in the queue have to be sent
The benchmark RRM architecture is presented in the next figure.
Here the illumination plan is not optimized at each iteration, but it is provided as input and a Round Robin scheduling approach is applied.
Plan
The Romantica study addresses 4 Tasks:
- Definition of a system scenario to be considered when investigating the innovative RRM algorithms (coverage, satellite configuration, user terminals, traffic models)
- Investigation of two solutions, a Benchmark algorithm (beam hopping and packet scheduling with separated optimizations) and an Advanced RRM algorithm that optimizes at the same time the system resource planning and the packet scheduling management
- Design of the architecture of the RRM, defining the functions implemented in the different parts of the system architecture (satellite payload, Gateways, dedicated Network Management System facilities)
- Development, validation and test of the RRM demonstrator tool
Current Status
The project has been completed. The final RRM Demonstrator software has been developed and tested successfully.
