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The paper carries out a preliminary assessment of how mobile satellite broadcasting (MSB) systems can increase their capacity potential with a high degree of flexibility and, at the same time, remain on par with wireless terrestrial counterparts. As argued in this work, a promising way forward in this regard is the migration from the conventional single polarization per beam to an advanced dual polarization...
Considerable efforts are being made in the area of interactive satellite broadcast services to mobiles, which range from the development of specific communication standards to the realization of practical proof-of-concept prototypes. The main reasons for such a big interest lie in the fact that interactive satellite services are a large potential market with many possible applications. Frequent and...
This paper gives an overview of a suitable communications system capable of efficiently use the available S-band allocation for pan-European Mobile Satellite Services (15 MHz in both uplink and downlink for each of the two licensed operators) to provide different classes of services such as interactive mobile broadcast services enhancing DVB-SH offer, messaging services for handheld and vehicular...
This paper describes an innovative receiver architecture for the satellite-based Automatic Identification System (AIS). The receiver performance has been fully validated in the presence of the typical satellite channel characteristics. In particular, it is shown that the devised receiver provides an excellent performance against the noise, as well as a large resilience against message collisions,...
Current Ka-band, multi-media satellite systems employ spot beam technology to accommodate a wide range of multi-media type services. These satellites typically employ uniform allocation of RF power and bandwidth to spot beams. Since the traffic distribution tends to be highly asymmetrical and with a high degree of uncertainty, the satellite does not have sufficient flexibility to satisfy the traffic...
This work presents an innovative, adaptive and optimal approach for Slotted-ALOHA protocols in Satellite Networks. Most ALOHA random access protocols are based on the assumptions that: i) all the involved stations receive packets with the same rate and ii) the transmission probabilities, computed analytically, are the same for each station. These assumptions are too optimistic, since, in real scenarios,...
The length and the frequency of the visibility times during which a fixed ground station sees a non-geosynchronous satellite is a function of the parameters of a fixed ground station and a function of the orbital parameters of the satellite. The focus, in this paper, is on the mean revisit frequency of a non-geosynchronous satellite with non-repeating ground track as seen by a fixed ground station...
Aircrafts in commercial routes have been proposed in some previous work as a novel DTN bundle carriers. Satellites can be one of the hops in this application. DTN suffers from intermittent disconnections, long delays and has scarce resources. It is a challenge to control the admission to these resources to provide better QoS and ensure optimum resource utilisation. Furthermore, providing fairness...
This paper presents the work that is currently performed in the E-SPONDER (FP7-242411) project. E-SPONDER is a project co-funded by the European Commission under its Security Program. E-SPONDER is a suite of real-time data-centric technologies that will provide information and communication support to first responders which act during normal and abnormal events (crises). It will investigate the use...
Advanced communication and broadcasting systems use heavily diversity techniques to improve service availability. To analyze the performance of systems using techniques such as time diversity or time interleaving, antenna diversity and angle diversity, a detailed knowledge of the channel characteristics is essential. Especially the statistical analysis and the evaluation of the slow fading effect...
In this paper, we propose an enhanced cooperative transmit diversity scheme in integrated mobile satellite service (MSS) systems. The proposed scheme is an efficient technique to adapt various power differences between a satellite signal and CGC signals, depending on the position of user equipments in integrated MSS systems. In the proposed scheme, we utilize modified space-time block coding (STBC)...
In this paper a novel optimal bit allocation for APSK modulation is proposed. Optimization is done by GA according to the satellite channel error sensitivity of the data. Furthermore, a new bit mapping is proposed for 16-APSK and 32-APSK. Results show the improvement of the proposed scheme with respect to the state of the art of the APSK modulation.
We propose and analyze two strategies to provide different levels of quality of service (QoS) to the DVB-SH standard. An extension of the interleaving scheme is investigated to support low latency service requirements for interactive services based on short messages. The first approach is a straightforward extension of the DVB-SH interleaver scheme based on an early-uniform interleaver profile, and...
In this paper, an overview of recent achievements in the design and decoding of non-binary low-density parity-check (LDPC) codes is provided. Non-binary constructions based on ultra-sparse matrices are compared with binary low-density parity-check codes and turbo codes from satellite communication standards, to show that larger coding gains (outperforming the binary competitors by at least 0.3 dB)...
A recent study of an European consortium (TPZ, Carlo Gavazzi Space, Edisoft, Elman, ITS) led by Telespazio and co-financed by ESA has investigated about the possibility of receiving AIS signals (i.e., AIS transmissions of vessels equipped with regular AIS transponders) from space with an improved performance with respect to the current literature thanks to an optimized mission design and enhanced...
In this work, we examine the feasibility of achieving Subspace Interference Alignment (SIA) in a multibeam satellite interference uplink channel. The channel is assumed to be Line-Of-Sight where link is a single physical path with complex gain and a large fixed delay (e.g. GEO satellite). SIA achieves interference-free degree of freedom in cellular networks owing to the rich scattering present in...
Several communication environments, supporting important operational scenarios such as deep space communications, Earth observation and mobile terrestrial communications, are extremely challenging for traditional TCP/IP protocols because of their intrinsic characteristic to not guarantee continuously an end-to-end path. An attractive application scenario is concerned the presence of terminals moving...
In this study, the Symbol error rate (SER) performance of cooperative based downlink satellite system with single terrestrial relay is investigated by using amplify-and-forward cooperation protocol over non identical fading channels. A closed form expression of exact SER over non identical fading channels is derived for M-ary phase shift keying (M-PSK) and M-ary quadrature amplitude modulation (QAM)...
A key requirement for the future multi-beam broadband satellite design is the provision of flexibility to adapt to different traffic demands by re-assigning capacity to beams in accordance with changing traffic distributions. Such flexibility would enable the best match to be maintained between the system resources and traffic demands over the satellite lifetime, thereby greatly enhancing the system...
Dimensioning the mobile link for aeronautical communications between aircraft and the satellite is a critical issue due to the limited power available, in particular if an omnidirectional antenna is used on board the aircraft. Also there are large channel variations due to the different effects occurring on the L-band mobile link and over-dimensioning of the user terminal or satellite should be avoided...
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