The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
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,...
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...
An important system in the field of global maritime surveillance is the Automatic Identification System (AIS), which is responsible for communicating ship- and voyage-related data of surface vessels. In order to improve the performance of the existing land-based AIS system, a consortium led by OHB has been responsible for the development of a full-fledged European space-based AIS system. The main...
The increased interest around the concept of "physical layer network coding" has generated a whole range of different technical solutions to implement it, which tradeoff complexity at the different elements of the network. While the effectiveness of this concept has been safely established for the two way relay channel, far less investigation has touched more sophisticated topologies, neither...
In this paper we extend the analysis of by comparing delay in protocols using retransmission and packet encoding for bidirectional unicast communication over a satellite channel, where the signal propagation delay is significant. We derive results on the total sender-receiver delay based on analysis and computer simulation for a Bernoulli packet arrival distribution.
Mobile terminals communicating through satellite suffer from low channel quality due to the combination of slow and fast fading and limited battery power. Moreover, the advanced applications proliferating over such terminals forbids the use of feedback based packet retransmission schemes over satellite due to their high latency, exceeding three times the round trip time. These feedback based packet...
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...
Delay-/Disruption-Tolerant Networking represents an innovative way to cope with satellite communications impairments. In this view, the paper presents an in-depth analysis of implications of a DTN approach to satellite communications, focusing on these fundamental aspects: network architecture, security, and Quality of Service (QoS). For each topic, commonalities and differences between DTN and Performance...
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 paper we investigate the degradation in FEC performance of LTE and WiMAX air-interfaces in satellite mobile channels due to lack of sufficient time diversity caused by the use of a short transmit time interval (TTI). We then propose a generalized `split multicode transmission' technique to overcome this problem without any reduction in the achievable user data rate. Simulation results are...
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)...
The development and performance of a hardware-prototype multi-user detection (MUD) receiver for Inmarsat's Broadband Global Area Network (BGAN) is described. The MUD receiver is used to compensate increased adjacent channel interference due to reduced channel spacing and can simultaneously detect up to six bearers in a 200-kHz satellite subband. With this technique, the channel-spacing can be reduced...
In response to the Digital Britain Interim Report published in the UK in 2009, which mandated that every home must have access to broadband at 2Mbps, Avanti is developing HERCULES - a two satellite multi-spot beam Ka-band system covering the UK and Ireland. HERCULES is designed to provide Universal Service Commitment (USC) services in the UK to two million homes (10% of the population) and Next Generation...
This paper presents current status, progress and next steps of the largest standardization effort conducted for satellite communication systems. We highlight the process, in order to understand the mechanisms involved, and novel technology elements. We also allow ourselves to speculate on the possible impact this work can have for the satellite community and see how opportunities for some interesting...
The new generation multi-spot Ka band satellites increase dramatically the offer of capacity whose cost is consequently reduced and give promising perspectives for fix interactive broadband services and mobile services. However, if on one hand the market and deployment of fix interactive broadband services definitely benefit from Ka band, on the other hand concerning mobile services the drawback of...
This paper aims at forecasting the role of Satellite Communications (SatCom) in the context of Future Internet and particularly of the future Internet-enabled smart infrastructures in support of some European Societal Grand Challenges. It also aims at identifying the necessary technological enablers which need to be developed by the European SatCom industry for the emerging SatCom solutions.
On-Board Processing (OBP) technology has been already in the satellite scene for almost two decades. It has been a difficult path and for a long time considered an added but expensive value brought to the satellite payload. Today, it is a commercial and competitive reality. In the case of Thales Alenia Space (TAS), a new generation of OBP solutions are available to satisfy the always more demanding...
This paper analyzes the possibility to perform joint frame synchronization and code acquisition for the DVB-RCS mobile system. Since the standard foresees the adoption of Direct Sequence Spread Spectrum techniques, novel detectors able to cope with the scenario at hand are proposed. Comparison in terms of Mean Acquisition Time and complexity are carried out, and the best solution in terms of performance...
This paper deals with design of the appropriate time domain equalizer based on DVB-S2 specification for mobile application. Firstly, we consider different ISI effect under various channel condition through field measurement. With reflection of channel effect, we suggest adaptive filter as channel condition and synchronization step mode like code start/hot start. Finally, we implement the blind FS...
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...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.