Florian Collard

From S‐band mobile interactive multimedia to fixed satellite interactive multimedia: making satellite interactivity affordable at Ku‐band and Ka‐band

This paper describes the evolution of the ETSI S-band mobile interactive multimedia protocol to support fixed satellite interactive multimedia F-SIM services exploiting existing Ku-band and Ka-band satellites. The key F-SIM protocol differences for both physical and upper layers are described and justified. The F-SIM protocol has been adopted by the recently deployed Eutelsat Broadcast Interactive System whose architecture, key system parameters, link budget examples and key composing elements are also described. Finally, a summary of laboratory and field trials results over the Eutelsat KA-SAT multibeam satellite are illustrated. Copyright

Performance Analysis of an Enhanced Spread Spectrum Aloha System

In this paper we present tests results of the first platform implementing a high performance Random Access protocol dubbed Enhanced Spread Spectrum Aloha (E-SSA), conceived for satellite applications. The aim of the study is to highlight key features of the system, introducing experimentally-found threshold values and translating them into operating conditions. A system overview is provided together with a summary of the most relevant parameters and the framework of the tests. The preamble detection and the packet demodulation processes are analysed, showing the importance of exploiting Successive Interference Cancellation techniques (SIC). It is shown that the code collision, due to a robust rate in the turbo-code and to the iterative cancellations, does not affect the system performances. Finally, Packet Loss Ratio (PLR) in presence of received carrier power and frequency unbalance is detailed with the aim of simulating more realistic scenarios.

E-SSA satellite messaging return channel: Performance analysis and field trials results

An open ITS platform combining interactive satellite services with other communication channels is being developed and evaluated in field trials within the SafeTRIP project. Prototyping and in-field validation of a novel waveform for messaging return channel over satellite for land mobile is an important objective of the project. The overall system architecture has recently been standardized by ETSI under the name of S-MIM (S-band Mobile Interactive Multimedia). The messaging protocol, described in the Part 3 of the standard, is based on the Enhanced Spread Spectrum Aloha (E-SSA). Its main asset resides in the low power required at the transmitter, which will allow the reuse of off-the-shelf power amplifiers and low-cost omnidirectional antennas. This paper will present a comprehensive summary of previous E-SSA performance analysis from simulations and the first field trials results using the E-SSA waveform. The presented results have been derived from static and mobile field trials carried out in Germany with fully functional E-SSA modulator and demodulator prototypes and the EUTELSAT10A satellite. Results for the static and mobile performance of the E-SSA demonstrator with an omni-directional antenna under Line-ofsight (LOS) conditions are presented. The measured Packet Error Rates of transmissions via satellite at different terminal power levels confirm the theoretical link budget calculations for single and multiple simultaneously transmitting terminals. The degradation due to fading effects of the transmission channel under mobile conditions has been measured during the trials to approx. 3 dB. The resulting overall required transmitter power in the multi-user scenario of the trials setup has been only -3 dBW to reach a high QoS under mobile conditions. This value confirms the suitability of the E-SSA waveform for interactive mobile services for the mass market.

Enhanced spread spectrum aloha demodulator implementation, laboratory tests and satellite validation

SUMMARY This paper describes the implementation of the first enhanced spread spectrum aloha demodulator, based on an innovative architecture which combines software-defined radio with processing via commercial graphics processing units. The validation tests performed both in laboratory conditions and directly on the satellite EUTELSAT 10A are presented. The performance assessment results obtained via satellite validate the theoretical results to a sufficient degree to make enhanced spread spectrum aloha technology a viable option for low-power mobile and fixed terminals, thus encouraging the growth of satellite mass market applications. Copyright

S-MIM field trials results

An intelligent transport system open platform integrating the S-band Mobile Interactive Multimedia messaging return channel protocol over satellite (based on Enhanced Spread Spectrum Aloha) has been developed and tested under real environment conditions within the framework of SafeTRIP, an FP7 EU-funded project. This paper presents the first field trials results using the S-band Mobile Interactive Multimedia technology. The introduced forward and return link outcomes have been derived from mobile field trials carried out in the surroundings of the German Aerospace Center (DLR) in Germany. Finally the validation of the system performances has been realized thanks to the use of a traffic emulator that can simulate a large population of Enhanced Spread Spectrum Aloha terminals.

Performance analysis of the S-MIM messaging protocol over satellite

In this paper we present experimental results of the ETSI S-MIM (S-band Mobile Interactive Multimedia) protocol, tested for the first time over a real GEO satellite (EUTELSAT 10A) and through a fully compliant ground platform. In particular, the employed radio interface implements the Part 3 of the standard, i.e. the asynchronous access protocol, especially conceived for the interactive messaging services. The performance assessment done by satellite validates the theoretical results and opens the way for the exploitation of low-power mobile and fixed terminals, thus allowing the proliferation of satellite mass market applications.

Performance analysis of the S-MIM messaging protocol over a Land Mobile Satellite (LMS) channel using a simplified transmission control algorithm

In this paper we present experimental results of the ETSI S-MIM (S-band Mobile Interactive Multimedia) standard, tested for the first time with the introduction of a Land Mobile Satellite (LMS) channel and through a fully compliant demodulation platform. In particular, the employed interface implements the Part 3 of the standard, i.e. the asynchronous access protocol, especially conceived for the interactive messaging services. The interest of this paper resides in the fact that the performance assessment, taking into account more realistic mobile scenarios, validates the theoretical results and opens the way for the exploitation of low-power mobile terminals, targeting automotive applications with extended coverage in suburban areas.