The purpose of the activity is to study, develop and validate key technologies for a baseband modem prototype for an M2M/SCADA terminal for star network applications, particularly focusing on fixed assets applications, and exploiting the full capabilities offered by DVB-RCS2 specifications. The task will be accomplished by building a demonstrator implementing a complete end-to-end system, including a realistic channel emulator. The project is split in two phases: Phase 1 will be focused on system scenarios and cost analysis, to determine the advantages of the proposed solution; Phase 2 the demonstrator will be designed developed and tested in laboratory environment.
Starting from the present existing satellite implementation of M2M services, the project intend to validate the key technologies for the development of a baseband modem prototype optimized for the specific application.
In the first phase 4 system scenarios will be defined on which the proposed technologies will be evaluated from the performances and cost standpoints. The study will address fixed terminals operating on geostationary satellite systems bearing in mind the objective to reduce the cost to the user for the service.
The consolidation of the system scenarios and the identification of the most promising techniques for the modem development will complete Phase 1, at the end of which the set of requirement for the test-bed will be made available to ESA, who, on the basis of the compliance with the study objective, will decide to proceeding with Phase 2.
Phase 2 will include the detailed design, development and testing of the test-bed in a simulated environment to assess, during the validation and test campaign, the complete functional performance capabilities for at least one of the Scenarios defined in Phase 1. The project will be completed with the definition of the roadmap for the final product architecture.
Starting from the DVB-RCS2 standard, but not limited to that, the project intends to investigate potential air interfaces that can be conveniently used for M2M application. At physical layer both linear and non linear modulation schemes (e.g. Continuous Phase Modulation – CPM) will be considered for the test-bed implementation.
At the data link layer, the payload encapsulation will be dealt with, which will be optimised, taking into account the peculiar characteristics of the M2M payload, which in general consists of relatively reduced size packets.
Also the Medium Access Control – MAC shall be considered since M2M traffic profile completely differs with respect to other data application, such as Internet access. The typical network configuration is based on several terminals accessing a common hub with the traffic in the inbound direction highly unbalanced with respect to the traffic in the opposite direction. Further, the user traffic maybe sporadic and normally don’t follow a regular pattern. In those cases a random access to the communication resources is considered the straightforward implementation. However basic random access techniques suffer for their reduced efficiency; at that regard, cancellation techniques will be considered in the perspective of performance improvement.
Prevention of overload situations is a key topic in random access networks: the system throughput increases with offered load until a threshold is reached; after that the throughput decreases. To prevent the occurrence of overload conditions, suitable mechanisms shall be inserted in the control and management plane.
A possible implementation of the modem prototype is sketched in the following diagram:
The architecture is proposed in order to optimize the architecture to achieve the goal of low cost / high reliability / small form factor. At that regard, the possible architectural solutions foresee either a traditional Outdoor / Indoor split or a more compact implementation embedding the complete terminal in the outdoor unit.
The project is split in two phases, the first phase dedicated to the system analysis and analytical performance evaluation and the second phase dedicated to the implementation of the laboratory demonstrator and the test campaign. In details:
The project key issues can be summarised as follow:
Machine-to-Machine (M2M) communications is presently a niche of satellite telecom market, counting for less than 2% of the total in terms of revenues. It is nevertheless promising because its sustained growing rate pulled by the expansion of computer controlled appliances and the consequent need of their accurate and secure control.
The presently available implementations make in general use of infrastructures not specifically designed for the specific topic and consequently not optimised in terms of performances and cost. The M2M project intends to analyse in details the potential improvements that a specific design could provide in view of the cost reduction and performance enhancement, which in turn are expected to further expand the service demand, its penetration and will enlarge the customers’ base.
Current Status (dated: 31 May 2013)
Task 1 has been completed with the approval of the relevant reports.
Task 2 has been completed with the selection of the air interface to be developed for the demonstrator in Phase 2. This is DVB-S2 LDR in the forward link and an adaptation of S-MIM for fixed services in the reverse link.
The advantages of this spread-spectrum technique, with respect to the originally proposed RCS2 baseline, have been demonstrated by means of simulations and analyses.
On that basis, the preliminary architecture and design is currently undergoing.
The project experienced a delay with respect to the original schedule: a contract extension of Phase 1 till October 2013 has been proposed with a CCN.