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The following topics are dealt with : network coding; automatic identification system; delay tolerant networks; modulation and coding; system architecture; estimation and synchronization theory; multibeam communication; cooperative communication; spectrum sharing; navigation and positioning; signal processing; communication theory; S-band system; and network protocol.
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...
The benefits of network coding in terms of throughput, security and robustness are well understood for a large class of networks, such as wireless mesh networks and peer-to-peer systems. We ask if similar performance enhancements can be attained in satellite based communications. Our feasibility study focuses on GEO satellite communication systems including regenerative payloads and multi spot-beam...
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...
Future deep space missions are envisioned to implement the Delay Tolerant Network architecture and to offer very high data rate also towards remote planets to support possible human missions. In this perspective, the need for advanced transmission paradigms and reliability means is needed to ensure the success of such missions. On the one hand, the CCSDS protocol implemented at the application and...
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...
Delay Tolerant Networking (DTN) has been proposed as a global overlay architecture to provide network connectivity in challenged environments such as deep-space communications field. Bundle Protocol along with its convergence layer protocols transform end-to-end reliability into questionable hop-by-hop reliable communication and imposes a two-tier routing policy that allows flexible routes only within...
Contact Graph Routing is a routing scheme for Delay-and Disruption-Tolerant Networks (DTNs) that is designed particularly for use in highly deterministic space networks. The Endpoint Discovery Protocol is designed for use in terrestrial DTNs where opportunistic contacts are common. We outline two scenarios where use of both of these protocols could be desirable and analyse the current versions to...
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...
A turbo code that is based on an 8-state binary constituent code is considered in this paper for use in an adaptive coding and modulation system for a return satellite link. The paper presents the results of finding good puncture-constrained dithered relative prime interleavers along with data puncture patterns to provide the required performance. A tradeoff between waterfall and flare performance...
In frequency division multiplexed (FDM) systems, spectral efficiency can be increased by reducing the spacing between two adjacent channels, thus increasing the relevant interference and possibly accounting for it at the receiver. In this paper, we consider a FDM system where each user employs a continuous phase modulation (CPM), serially concatenated with an outer code through an interleaver, and...
The Scalable Video Coding (SVC) is an extension of H.264/AVC offering temporal, spatial, and quality scalability. Compared to the non-scalable profile of H.264/AVC, SVC allows layered transmission of video data. Variable Coding and Modulation (VCM) based DVB-S2 Video Broadcasting Systems enables effective selection of modulation modes and FEC code-rates offering differentiated error protection. In...
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