Traditional terrestrial computing facilities, i.e., Edge Computing (EC) and Cloud Computing (CC), have limited applicability for remote Internet of Things (IoT) applications due to connectivity challenges. These challenges can be addressed through a Space-Edge Cloud continuum that leverages computing facilities enabled by Low Earth Orbit (LEO) satellites and terrestrial cloud facilities. We aim to minimize the joint latency and energy cost for processing remote IoT data in this continuum by formulating a complex optimization problem. Specifically, our goal is to optimize the complete offloading process by jointly selecting optimal routes, computation nodes, and buffering policies. We develop a Multi-Agent Hierarchical Reinforcement Learning (MA-HRL) solution to solve this problem. The proposed solution is developed in a Python environment and compared with several benchmark methods, demonstrating significant performance gains in terms of reduced latency and energy demands.

The Internet of Things (IoT) is one of the most important applications in a distributed edge-cloud continuum. In this study, we aim to solve the data offloading and buffering policy selection problem for the remote IoT devices to process the data over the space edge cloud continuum formed by the non-terrestrial Edge Computing (EC) facilities, deployed over Low Earth Orbit (LEO) satellites, and the terrestrial cloud infrastructure. In particular, we have developed a constrained optimization problem to minimize the joint latency and energy costs associated with the data processing operation over LEO satellite nodes and cloud facilities. The problem is then decomposed into a hierarchy of decision-making subproblems and addressed using a Hierarchical Reinforcement Learning (HRL) approach. The proposed HRL solution is then implemented within a Python-based simulator, and its performance is compared with several other benchmark solutions. Performance analysis indicates the gain in terms of latency, energy, and resource utilization with adaptive utilization of space computing resources based on the devices’ demands.

To build the new generation of ubiquitous communication and service integration networks with “network omnipresence and computing ubiquitous,” it is urgent to improve the in-orbit computing ability of low earth orbit (LEO) constellation networks and develop intelligent technology for satellite–ground collaborative edge computing. Communication tasks between ground nodes and satellites are increasing, but the satellite-to-ground spectrum resources are limited. The reasonable application of channels determines the performance of the network, which in turn affects the users’ experience. An outstanding issue is how to allocate channels rationally and control the power of data transmission to reduce co-channel interference and minimize system overhead effectively. This article studies multiuser computation offloading for low earth orbit (LEO) constellation networks under dynamic environment, wherein the system overhead is minimized by joint offloading strategy and power optimization. First, we propose a generic network architecture for computation offloading of LEO constellation networks under the dynamic environment. Then, from a game-theoretic perspective, we model the overhead minimization problem as a potential game and prove that the Nash equilibrium (NE) minimizes the system overhead. After that, to reach the NE, we design the Synchronous log-linear learning-based power control algorithm and joint offloading strategy and power optimization algorithm based on SLA (JOPAS), and prove the convergence of the algorithms. Finally, the effectiveness of the proposed algorithm is verified through extensive simulations and comparisons with benchmark algorithms, and the proposed algorithm achieves near-optimal performance.

Several actuation choices in the Internet of things (IoT) require state information to be up-to-date. In this context, the choice between local processing and offloading to a more powerful remote server can have a significant impact on data freshness. Local processing is indeed typically less reliable due to limited computing power and may require multiple attempts, which can result in data becoming stale. Conversely, remote (i.e., edge/cloud) processing can be more reliable, yet entail longer response times due to data transmission to an external server, possibly performing processor sharing with other tasks. The optimal balance depends on the specific system conditions, especially on the congestion at the remote server, and is in general non-trivial. We explore this tradeoff through a mathematical model, and argue about the derivation of a freshness-efficient local vs. remote split of requests, providing insights on the role played by reliability and latency in selecting the optimal strategy.

Internet of Space Things (IoST), which extends the concept of Internet of Things (IoT) to space, has emerged as a new paradigm for offering monitoring/reconnaissance, in-space backhaul, and cyber-physical integration services. As Low Earth Orbit (LEO) satellites are increasingly deployed for global Internet services, Mobile Edge Computing (MEC) is being introduced into satellite networks to provision computing services by placing edge servers on satellites. Nevertheless, it is a nontrivial and unexplored task to efficiently choose edge server deployment locations from a large number of satellites. In this paper, we address this issue in detail towards average response delay minimization considering propagation delay, forwarding delay, and service delay. In particular, we formulate the dynamic server placement problem as well as the static server placement problem, and devise a genetic algorithm-based heuristic approach to solve them. Simulation results compare the two placement strategies with two benchmarks and demonstrate the performance of our genetic algorithm-based approach. Furthermore, a comparison between the dynamic placement and the static placement is investigated.

To satisfy the explosive access demands of Internet-of-Things (IoT) devices, various kinds of multiple access techniques have received much attention. In this article, we investigate the multicast communication of a satellite and aerial-integrated network (SAIN) with rate-splitting multiple access (RSMA), where both satellite and unmanned aerial vehicle (UAV) components are controlled by network management center and operate in the same frequency band. Considering a content delivery scenario, the UAV subnetwork adopts the RSMA to support massive access of IoT devices (IoTDs) and achieve desired performances of interference suppression, spectral efficiency, and hardware complexity. We first formulate an optimization problem to maximize the sum rate of the considered system subject to the signal-interference-plus-noise-ratio requirements of IoTDs and per-antenna power constraints at the UAV and satellite. To solve this nonconvex optimization problem, we exploit the sequential convex approximation and the first-order Taylor expansion to convert the original optimization problem into a solvable one with the rank-one constraint, and then propose an iterative penalty function-based algorithm to solve it. Finally, simulation results verify that the proposed method can effectively suppress the mutual interference and improve the system sum rate compared to the benchmark schemes.

Future space missions are expected to implement a fully compliant CCSDS-DTN protocol stack in order to exploit the intrinsic store-forward capabilities. DTN technology, however, is not aimed at providing ordered data delivery, which is instead delegated to the application layer. More recently, the Delay-Tolerant Payload Conditioning (DTPC) has been introduced into the DTN protocol suite in order to mitigate such a limitation, although its interactions with application layer and the rest of the CCSDS protocol stack are not completely understood. To this end, this paper proposes a theoretical model for thoroughly investigating the performance of file-based data transfer through a CCSDS-DTN protocol architecture. A qualitative performance analysis allowed to summarise some important findings about overall protocols' configuration and the related impact on the overall system performance.

Offering very large data rates is one of the main objectives of Very High Throughput Satellite (VHTS) systems to boost enhanced Mobile Broadband (eMBB) services in converged 5G-satellite systems. To this end, the exploitation of Q/V frequency bands for the satellite feeder link is a key factor for guaranteeing unprecedented data rates provided that efficient handover algorithms are implemented to counteract link outage events caused by severe weather impairments. Moreover, Quality of Service (QoS) of data flows is typically affected when gateway handover is initiated, hence calling for sophisticated ground segment management solutions. In this light, this paper proposes a novel gateway handover strategy and validates its design through simulation campaigns, whose preliminary results show important performance gains with respect to other solutions available from the existing literature.

The expansion of the maritime industry with the increase of ship data traffic calls for the support of satellite communications not only for bandwidth-hungry applications for passengers and crew but also for Internet of Things applications. In this paper, we address the problem of efficiently managing the distribution of the vast amount of sensor data from ships to remote control centers and harbor authorities. An efficient solution to tackle this problem is adopting an Information-Centric Networking (ICN) approach. ICN is based here on Named Data Networking (NDN), which is one of the most efficient ICN approaches. We propose an efficient naming scheme for NDN, where the processing of local data from sensors allows improving the mean delay to deliver the sensor data. A simulation approach has allowed us to validate our proposed approach against the hierarchical naming scheme of NDN.

In the context of the 5G ecosystem, the integration between the terrestrial and satellite networks is envisioned as a potential approach to further enhance the network capabilities. In light of this integration, the satellite community is revisiting its role in the next generation 5G networks. Emerging technologies such as Software-Defined Networking (SDN) which rely on programmable and reconfigurable concepts, are foreseen to play a major role in this regard. Therefore, an interesting research topic is the introduction of management architecture solutions for future satellite networks driven by means of SDN. This anticipates the separation of the data layer from the control layer of the traditional satellite networks, where the control logic is placed on programmable SDN controllers within traditional satellite devices. While a centralized control layer promises delay reductions, it introduces additional overheads due to reconfiguration and migration costs. In this paper, we propose a method to quantify the overhead imposed on the network by the aforementioned parameters while investigating the use-case scenario of an SDN-enabled satellite space segment. We make use of an optimal controller placement and satellite-to-controller assignment which minimizes the average flow setup time with respect to varying traffic demands. Furthermore, we provide insights on the network performance with respect to the migration and reconfiguration cost for our proposed SDN-enabled architecture. Finally, we compare our proposed space segment SDN-enabled architecture with alternative solutions in the state-of-the-art given the aforementioned performance metrics.

The growth of Internet traffic especially with respect to mobile broadband services is one of the main motivations towards the integration of satellite and 5G networks. A key building block for the overall network orchestration will be the efficient definition and management of network slices, which eventually translates into efficient allocation of physical and computing resources. This paper explores the resource allocation problem in the case of railway communications building on satellite and 5G connectivity. Some exemplary candidates solutions have been elaborated, whose validation through simulation campaigns has shed some lights about the main factors impacting on the overall system performance and the most effective resource allocation solutions.

In this paper, we propose a novel zero-forcing (ZF)- based beamforming (BF) scheme for a wireless powered cognitive satellite-terrestrial network (CSTN) operated in the millimeter wave band. Assuming that the satellite and base station are equipped with multiple antennas, we aim at maximizing the sum rate of the CSTN while satisfying the signal-to-interference-plus-noise- ratio requirements for both the information receivers (IRs) and earth stations, the energy harvesting requirements of the energy receivers (ERs), and the secrecy constraints at the ERs. Since the resulting optimization problem is mathematically intractable, we propose a novel multi-beam-based ZF BF scheme to generate beamforming vectors to serve the IRs and ERs. Specifically, the original nonconvex problem is decomposed into two independent subproblems. The first subproblem, which features beam orthogonality constraints, leads to closed form solutions for the beamforming vectors. The second subproblem, aiming at finding the optimal power allocation, is solved via the S-procedure. Finally, the effectiveness of the proposed scheme is demonstrated by simulation results.

Providing reliable and efficient connectivity for maritime systems is a key objective to enable new services and to offer anytime-anywhere communication solutions to vessels operating in remote areas (e.g. oceans). Such a task has recently become quite compelling because of the increasing maritime traffic, which should be supported by an information distribution infrastructure in order to guarantee efficient data communication among vessels and control centres on land. To this end, satellites are the perfect candidates for achieving such an objective. This paper focuses on the case of messaging from moving vessels to fixed control centres on land by means of advanced channel random access schemes exploiting time diversity. In more detail, the paper extends an existing theoretical framework to evaluate the packet loss probability in Framed Slotted ALOHA systems by delving into the probability distribution of both colliding users within a frame and their replicas in time slots. The theoretical framework is validated through simulations campaigns, showing a good match between analytical and simulated results.

This paper proposes a beamforming (BF) scheme with non-orthogonal multiple access (NOMA) for a cognitive satellite-terrestrial network (CSTN), where the satellite network shares the radio frequency bandwidth with the terrestrial network. By assuming that the satellite adopts multicast technology to serve several satellite terminals (STs), while the base station (BS) employs the combination of BF and NOMA to significantly enhance the spectrum efficiency, we aim at maximizing the sumrate of the considered CSTN under the constraints of per-antenna power budget and the quality of service (QoS) requirements for desired cellular users (CUs) and STs. Then, based on the S-procedure and Taylor approximation approach, we present a method to convert the nonconvex problem to a solvable one with linear constraints, and obtain the optimal BF weight vectors through iterative procedure. Finally, numerical results demonstrate the validity and superiority of our proposed scheme.

Recently, the availability of innovative and affordable COTS (Commercial Off-The-Shelf) technological solutions and the ever-improving results of microelectronics and microsystems technologies have enabled the design of ever smaller yet ever more powerful satellites. The emergence of very capable small satellites heralds an era of new opportunities in the commercial space market. Initially applied only to scientific missions, Earth observation and remote sensing, small satellites are now being deployed to support telecommunications services. This review paper examines the operational features of small satellites that contribute to their success. An overview of recent advances and development trends in the field of small satellites is provided, with a special focus on telecommunication aspects such as the use of higher frequency bands, optical communications, new protocols, and advanced architectures.

This work analyses the use of the WebRTC framework on resource-constrained platforms. WebRTC is a consolidated solution for real-time video streaming, and it is an appealing solution in a wide range of application scenarios. We focus our attention on those in which power consumption, size and weight are of paramount importance because of size, weight and power requirements, such as the use case of unmanned aerial vehicles delivering real-time video streams over WebRTC to peers on the ground. The testbed described in this work shows that the power consumption can be reduced by changing WebRTC default settings while maintaining comparable video quality.

Software Defined Networking (SDN) has been identified as a potential approach to achieve a more flexible control and management of the traditional satellite systems and enhance the opportunities for future services including the possibility of a hybrid satellite/terrestrial network. Given the renewed interest towards Low-Earth-Orbit (LEO) constellations, an interesting research topic is the design of a suitable network management model taking into account user specific metrics. In this paper, we address this issue while investigating the use-case scenario of an SDN-enabled satellite space segment. A Dynamic Controller Placement Problem (DCPP) is considered for a LEO constellation where the traffic demands change dynamically based on users' geographical position and time zone. To this end, we develop a mathematical model and formulate it as an Integer Linear Programming (ILP) guaranteeing an optimal controller placement and satellite-to-controller assignment minimizing the average flow setup time with respect to the traffic dynamics. We show results for the DCPP regarding the average flow setup time. Furthermore, a comparison with respect to the static approach is investigated and the proposed SDN-enabled LEO constellation architecture is compared with alternative architectures proposed in the state of the art.

This special issue is devoted to Satellite Communication advances so as to gather the most important contributions in this field from academia and industry. In particular, the importance of this issue is also due to the fact that the last issue appearing on IEEE JSAC about SatCom is dated back to 2004 and therefore many important technology advances have been testified in the meantime, actually revolutionizing the satellite industry. In particular, important innovations have been brought to the design of both ground and space segments, spanning physical layers up to upper layers of the protocol stack.

This special issue is devoted to the satellite communications (SatCom) advances so as to gather the most important contributions in this field from academia and industry. In particular, the importance of this issue is also due to the fact that the last issue appearing on IEEE JSAC about SatCom is dated back to 2004 and therefore many important technology advances have been testified in the meantime, actually revolutionizing the satellite industry. In particular, important innovations have been brought to the design of both ground and space segments, spanning physical layers up to upper layers of the protocol stack.

The increasing demand for mobile services has been calling for new anywhere-anytime communication paradigms, building on the integration of heterogeneous technologies, such as satellite, LTE, and the new generation of mobile networks, i.e., 5G. In particular, the network design philosophy has shifted towards a more content-oriented approach so as to more efficiently meet the users' demands in terms of fast content availability and service continuity. Following this line, this paper proposes an enhancement to the PURSUIT information centric network (ICN) architecture, so as to improve the quality of experience of users in highly mobile environments. Simulation campaigns show the performance gain offered by the proposed solution with respect to regular PURSUIT implementations and benchmark IP-based strategies.

Support of data communication during disaster management operations is traditionally achieved by means of Internet Protocol (IP)-based networks, which however show some limitation in terms of mobility support and resilience to link disruption. A new promising networking paradigm is represented by Information Centric Networking (ICN) architectures implementing caching functions, which are studied in this paper for their potentials to support emergency communications in integrated satellite-terrestrial networks. Simulation campaigns show the advantages offered by the Named Data Networking (NDN) architecture in terms of delivery latency and overall gain in comparison to IP-based architectures.

The design of High Throughput Satellite (HTS) systems builds on the concept of Smart Gateway Diversity (SGD) to exploit the spatial diversity of gateways in case of feeder link outage, occurring because of atmospheric impairments introduced in Extremely High Frequency (EHF) frequency bands. The gateway handover procedure requires precise prediction algorithms and coordination among different network elements. This paper presents novel outage prediction algorithms based on machine learning concepts, integrated in the framework of SDN architectures, to efficiently orchestrate the gateway handover operations. Simulation campaigns prove the validity of the proposed concept and shed light on the potentials of the SDN architecture in future HTS systems.

New generations of public safety communications will be building on the top of LTE technologies, taking advantage of its improved performance in capacity and quality of service. LTE networks present a unique opportunity to provide innovative applications and networking solutions to first responders. Flexible LTE deployments using satellite backhauling are being investigated raising new challenges regarding the integration of these technologies. In this paper, a delay-tolerant approach for different priorities of traffic management in LTE cell interconnected using satellite backhauling is presented. Long propagation delays and frequent disruptions of satellite links bring several challenges, especially to map the LTE quality of service requirements for traffic. We design and evaluate Disruption Management Agent (DMA), which acts as bridge between LTE and satellite technologies for providing end-to-end Quality of Service (QoS). Simulations results using several scenarios have shown the effectiveness of our solution to deliver an appropriate quality of service to first responders.

This paper proposes a quality of service (QoS) management framework for high throughput satellite (HTS) systems using extremely high frequency (EHF) frequency bands, which can achieve high capacity provided that feeder link outage events caused by severe weather conditions can be properly counteracted. To this regard, smart gateway diversity architectures implementing advanced gateway handover procedures are certainly attractive, although they can only partly mitigate the negative effects of adverse weather conditions in terms of packet losses, delays, and jitters, which significantly degrade the performance of delay-sensitive and delay-insensitive traffic flows. To cope with these technical challenges, we propose an incremental rerouting scheme to control congestion events because of capacity reduction during the transient phase, consisting of offloading high-priority QoS traffic flows from the affected gateway towards gateways operating in more favorable conditions. Moreover, we apply inter-flow network coding at the gateways to protect delay-insensitive flows from packet losses occurring during feeder link outage. Finally, extra capacity is reserved at the gateways to handle the additional traffic resulting from gateway handover. The theoretical analysis (validated by simulation campaigns) allowed characterizing network coding performance and confirming the potentialities of our QoS management framework for HTS systems.

Application of random access schemes in the return link of satellite systems shows appealing advantages over demand assignment multiple access (DAMA) especially in case of bursty traffic (e.g., M2M). The interactions of TCP with random access has been however only marginally explored by the scientific community, thus limiting the appeal of random access. This paper attempts to bridge this gap, by providing insights into the performance of TCP-based services running on top of DVB-S2/RCS2 satellite networks implementing Contention Resolution Diversity Slotted Aloha (CRDSA) as random access scheme. A special attention has been also dedicated to TCP modeling, since classical TCP throughput formulations fail in the proposed scenario, whereby a simple but effective enhancement is proposed in this paper.

We study a queueing system operated with packet level coding. More specifically, we derive a closed form upper bound on the queueing delay as well as an expression for the decoding delay of a system operated with systematic network coding. Unlike previous works, the delay is considered on a per-packet basis rather than per-block, thus taking into account the low-latency property of systematic codes. Furthermore we study the tradeoff between the coding gain and the decoding delay defining the “achievable” region (packet loss vs. delay) for finite block lengths.

This paper studies the sum throughput maximization of the return-link in multi-beam satellite systems. Considering bursty communication scenarios with different users' data request probabilities, we develop an efficient scheduling scheme using genetic algorithms (GAs). Moreover, we consider co-channel interference (CCI) and adjacent channel interference (ACI). We consider a receiver with and without interference cancelation. Using a simplified channel model, we evaluate the proposed scheduler in a multi-beam system. The proposed GA-based scheduler approaches the throughput of an optimal scheduler based on exhaustive search with substantially less implementation complexity.

This paper explores the network design implications to be taken into account in Smart Gateway Diversity (SGD) satellite systems, where gateway outage events have to be counteracted by efficient handover procedures. In more detail, enabling high data-rate satellite systems in these conditions requires efficient coordination strategies between gateways, upstream routers and Network Control Centre (NCC) to precisely estimate the need of handover and to efficiently manage the satellite resources. To this regard, this paper adopts a simple channel estimation algorithm and applies network coding to cope with packet losses deriving from possible inaccuracies on the prediction of the handover time. The results obtained via simulation confirm the capabilities of network-coding-based approaches and pave the way for further studies in the area of network for SGD satellite systems.

This paper focuses on geostationary satellite scenarios and investigates the performance of several Transmission Control Protocol (TCP) variants in a novel Performance Enhancing Proxy (PEP) architecture solution, whose added value is the use of network coding beneath the transport layer. Comparison of TCP New-Reno, Vegas, Scalable, CUBIC, Hybla, and HTCP and the cases where these transport protocols are used along with network coding is carried out by means of simulation campaigns. The obtained results show the potentials of the proposed network coding technique, resulting in the improvement of TCP connections performance in a wide range of channel conditions and the possible exploitation of future increase of the satellite link capacity.

The design of alerting systems integrating various technologies (mobile, satellite, navigation), capable to reach anytime and anywhere population, is becoming of absolute importance for management of tomorrow crisis situations. In this respect, the paper explores the design implications arising when alert messages are sent over Global Navigation Satellite Services (GNSS). Extensions of GNSS system to transport alert messages are presented. The performance evaluation given at the end of the paper shows the efficiency of the design system in terms of average alert message delivery delay and confirms the potential of GNSS systems for future alert applications.

The most widely used transport protocols (i.e, TCP and UDP) are not suitable for aeronautical services because of the reliability and strict transfer delay requirements that cannot be met by TCP and UDP in such environment. In this respect, the paper proposes a novel message-oriented transport protocol Reliable Aeronautical Services Protocol (RASP) enabling reliable aeronautical services. Simulation campaigns carried out in ns-2 show the superiority of RASP with respect to TCP in terms of end-to-end message transfer delay and number of performed retransmissions.

Mitigation of Transmission Control Protocol (TCP) performance degradation over satellite has been extensively studied over the last two decades by the scientific community, which has come up with a large set of protocol and architecture solutions. This paper proposes a novel end-to-end (E2E) transport layer protocol, namely Advanced Transport Satellite Protocol (ATSP), which is built around consolidated control theory concepts already infused in Active Queue Management (AQM) control schemes. ATSP exploits the knowledge of the bandwidth allocated to each terminal, as available from the satellite network operator. Besides, the satellite network property of being completely under control allows the joint collaboration of sender, receiver and routers in order to acquire a complete knowledge of the network status and eventually optimize the overall performance. The performance analysis shows that ATSP achieves a fair bandwidth share for all the satellite users and outperforms TCP Hybla, which is optimized for satellite links, in terms of throughput.

Availability of higher capacity for both uplinks and downlinks is expected in the future deep-space missions on Mars, thus enabling a large range of services that could eventually support human remote operations. The provisioning for deep-space links offering data rate up to several megabits per second will be a crucial element to allow new services for the space domain along with the common telecommand and telemetry services with enhanced communication capabilities. On the other hand, also the geometry proper of this scenario with orbiting and landed elements sharing only partial visibility among them and towards Earth provides another challenge. This paper surveys the reliability options that are available in the Consultative Committee for Space Data Systems (CCSDS) Protocol Stack for application in the deep-space missions. In particular, the solutions implemented from the physical up to the application layer are illustrated in terms of channel coding and Automatic Retransmission reQuest (ARQ) schemes. Finally, advanced reliability strategies possibly applicable in next-generation deep-space missions are explored as well.

The features that DTN protocol architecture offers are particularly appealing to handle intermittent links and disruption events, by means of the Custody Transfer option. On the other hand, the implementation of long erasure codes proved to be promising to contrast short fading events in long delay networks, where the high latency makes the use of ARQ schemes less profitable. This paper proposes a protocol design to incorporate long erasure codes into the Bundle Protocol specification. The conducted performance analysis shows the benefits coming from this integrated approach but also points out the possible shortcomings deriving from the saturation of the buffer implemented at the Bundle Protocol layer.

In view of the dense and complex space network topologies envisioned for the future, the management of congestion control is a prominent issue that deserves a particular attention. Given the challenging peculiarities of interplanetary environments, this paper focuses on the advantages offered by storage-based routing and on potentials of implementing Random Early Detection (RED) and Explicit Congestion Notification (ECN) mechanisms within the Delay Tolerant Network (DTN) architecture. In this light, solutions relying upon the aforementioned concepts have been designed and tested. Preliminary results show that combination of RED and ECN schemes with network-selection strategies for storage-based routing is really promising and outperforms other solutions in terms of reliability, network resource utilisation and power consumption.

The networking and communication challenges posed by interplanetary environments make the design and the deployment of complex telecommunication infrastructures particularly difficult, especially with regard to routing and congestion control issues. To this end, the paper proposes a congestion-aware routing paradigm that applies multi attribute decision making (MADM) concepts for next-hop selection, by formulating an optimisation problem and proposing some possible resolution criteria. Effectiveness of the proposed solutions is assessed through a preliminary performance analysis that shows promising results.

Providing effective telecommunication services over interplanetary networks poses a number of open challenges because of severe impairments exhibited in such environment. In this perspective, this work proposes a coding framework, integrated within the delay tolerant network (DTN) architecture, implementing adaptive erasure coding schemes that rely upon partial observation of the transmission channel dynamics. Three main protocol solutions based upon partial observable Markov decision process (POMDP) and incremental redundancy adaptation (IRA) have been devised and analysed under different scenario configurations. The performance analysis showed promising results and the superiority of the proposed solutions with respect to approaches based upon fixed- rate coding strategies.

Providing effective telecommunication infrastructures for disaster relief and emergency operations can be achieved by taking advantage of anywhere-anytime communication capabilities offered by satellite and wireless technology. In this perspective, designing a network architecture able to ensure reliable and timely delivery of data, and able to resist against link disruption is of utmost importance. To this end, this work proposes a mobility-aided routing strategy, derived from other proposals, that aims at delivering data to destinations by taking into account power consumption issues. The efficacy of the proposed solutions is assessed by simulation, considering different scenario configurations.

Transferring data reliably from Mars to Earth stations is becoming an appealing challenge in the design of interplanetary networks. In this view, the use of CCSDS-based protocols along with erasure codes is a promising candidate for mitigating the performance degradation due to large propagation delays and high packet loss rates. Besides, the constraints imposed on the transmission power and on the available link bandwidth introduce further challenges to the design of the telecommunication system. In this paper, the benefits brought are investigated by tuning properly erasure code rate at the upper layers, pointing out the performance gain in terms of goodput performance and analysing power consumption and bandwidth usage issues, as well.

The paper describes a measurement campaign recently carried out by University of Bologna (UoB), National Inter-University Consortium for Telecommunications-(CNIT) and University of California Los Angeles (UCLA), on the CNIT GEO Skyplex platform. The aim of the experiments is the performance assessment of a wide range of TCP enhancements on network environments that include a real GEO satellite link. Measurements were carried out by means of the integrated UoB-CNIT testbed, fully controlled by remote through a Web interface. Analysis of live experiments data confirm the challenges posed by GEO sat channels, and show a negative influence of the Skyplex BoD technique on TCP start-up performance. Among the TCP enhancements compared in the paper, best results are provided by TCP Hybla and TCP Westwood, with an advantage of the former in heterogeneous environments characterized by a high level of RTT unfairness.

The extension of telecommunication frontiers towards deep space scenarios has opened new horizons in the way of designing network infrastructures and has raised the necessity of developing novel communication paradigms, more suited to this specific environment. Under this view, the exploitation of TCP-based transmission schemes does not offer satisfactory results. On the contrary, the use of erasure coding schemes and more appropriate automatic repeat request (ARQ) schemes, available within the transport layer coding-based and the Consultative Committee for Space Data Systems (CCSDS) protocol architectures, respectively, assure better performance results. In this paper, the adoption of erasure codes within CCSDS protocol stack is considered and its effectiveness is evaluated with respect to ARQ-based transmission schemes available within the CCSDS file delivery Protocol.

The rising demand for multimedia services even in hazardous environments, such as space missions and military theatres, and the consequent need of proper internetworking technologies have revealed the inapplicability of TCP/IP architectures and highlighted the importance of the communication features provided by the protocol architectures proposed by the Consultative Committee for Space Data Systems (CCSDS). This paper proposes a CCSDS File Delivery Protocol (CFDP) extension, based on the implementation of erasure coding schemes, in order to assure high reliability to the data communication even in presence of very critical conditions, such as hard shadowing, deep fading periods and intermittent links. Different encoding techniques are considered and various channel conditions, in terms of Bit Error Ratio and bandwidth values, are tested.

The paper concerns the study of transmission mechanisms employed in telecommunication environments, where LEO (low earth orbit) orbits are present Several investigations about novel network architectures have been produced in order to individuate the solution that meets all the network requirements and characteristics in terms of delay, reliability and speed. Two types of solutions are proposed: the first one, where the terminals are modified and no additional tool is inserted in the network; the second one, based on a protocol-splitting philosophy. This latter supposes to add special tools called gateways to improve the performance. The effectiveness of the proposed solution is then evaluated by using a software simulator that has been adapted for the communication in the different protocol architectures studied.