The economics of integration of DVB‐S with terrestrial technologies and the role of dynamic bandwidth management

This paper presents the technoeconomic aspects of network solutions based on integration of satellite and terrestrial, based on ADSL, WLAN and DVB‐T technologies, architectures. Following a discussion of the general deployment context, the business case framework is described in terms of areas served, services offered, tariffs, demand assumptions, as well as network architecture and dimensioning rules. The key cost items are presented and economic estimations are provided in the case of telecom operators, which integrate satellite bandwidth with terrestrial technologies in different area types. The evaluated business cases have shown that the satellite rental cost (airtime cost) level is one of the most critical parameter for the economic indicator of present value. Therefore, agreements with satellite operators for spectrum usage will give operators space for business opportunities and acceptable profit margins. In addition, dynamic bandwidth allocation schemes can exploit the aggregated traffic within satellite transmission, which can benefit satellite, telecom and cable operators offering entertainment on broadband business as well as new entrants in broadband business, equipment vendors, broadcasters and TV companies. Copyright © 2007 John Wiley & Sons, Ltd.     

IPv6 networks over DVB‐RCS satellite systems

Satellite plays an important role in global information infrastructure (GII) and next generation networks (NGNs). Similarly, satellite communication systems have great advantages to support IPv6 (Internet Protocol version 6) networks as a technology that allows universal access to broadband e‐services (audio, video, VPN, etc.). In the context of DVB‐S2 (digital video broadcast‐satellite) and DVB‐RCS (digital video broadcast‐return channel via satellite) standards, this paper presents the current SatSix project (satellite‐based communications systems within IPv6 networks) within the European 6th Framework Programme, which is implementing innovative concepts and effective solutions (in relation with the economical cost) for broadband satellite systems and services using the technology presented above. This project is promoting the introduction of the IPv6 protocol into satellite‐based communication systems. Moreover, through SatSix, the industry is addressing the next generation Internet, IPv6. It also enhances its competitive position in satellite broadband multimedia systems by exploiting the common components defined by the European DVB‐S2 and DVB‐RCS satellite broadband standards. Copyright © 2007 John Wiley & Sons, Ltd.     

Adaptive Coding and Modulation‐enabled satellite triple play over DVB‐S2 (Digital Video Broadcasting ‐ Satellite ‐ Second Generation): a techno‐economic study

This article looks at the techno‐economic perspectives of the use of DVB‐S2 (Digital Video Broadcasting ‐ Satellite ‐ Second Generation) and its unique feature, Adaptive Coding and Modulation (ACM) in the provision of satellite triple play. For this study, current market economic data were used, in conjunction with technical results derived within the European Union‐funded IST IMOSAN project. IMOSAN (Integrated Multi‐Layer Optimisation in DVB‐S2 Satellite Networks) succeeded in realising the provision of satellite triple play over an interactive DVB‐S2/DVB‐RCS (Return Channel via Satellite) platform. The ACM feature of DVB‐S2 was exploited, yielding increased spectrum efficiency and thus decreasing service cost. One‐user‐per‐terminal scenarios are examined, as well as terrestrial redistribution of satellite services to a group of users via WiMAX. Copyright © 2012 John Wiley & Sons, Ltd.     

Admission control and handover management for high‐speed trains in vehicular geostationary satellite networks with terrestrial gap‐filling

Following a recent upgrade, the Digital Video Broadcasting—Return Channel Satellite (DVB‐RCS) standard sets up to support terminal mobility. In this scenario, integration with terrestrial systems becomes a primary concern to ensure network connectivity in urban areas. This article proposes an integrated satellite–terrestrial architecture for the provision of broadband services onboard high‐speed trains, in which terrestrial cellular networks are seen as viable gap‐fillers for discontinuous satellite coverage. We derive an analytical model of the hybrid DVB‐RCS‐cellular system by exploiting analogies between the mobility pattern predictability of LEO constellations and that of high‐speed trains. Terminals whose QoS cannot be guaranteed by the satellite segment are proposed to temporarily divert the connections towards the terrestrial infrastructure, where available. Using an iterative approach based on the Erlang fixed‐point approximation, we show performance improvements with respect to stand‐alone satellite systems in terms of handover failure probability and overall resource utilization. The analytical model is also validated via our ns2‐based DVB‐RCS packet‐level simulator. Detailed modelling of synchronization and signalling mechanisms confirms the accuracy of the analytical results, and shows that topology and mobility information can contribute to refine radio resource utilization optimality when used jointly. Copyright © 2009 John Wiley & Sons, Ltd.     

Evolution of satellite communications: Integration of ETSI BSM and DVB‐RCS for future satellite terminals

The main added value of the European Telecommunications Standards Institute broadband satellite multimedia (ETSI BSM) architecture is the definition of the Satellite Independent‐Service Access Point (SI‐SAP) protocol interface, which formally separates Satellite Dependent (SD) from SI layers, thus enabling the implementation of powerful vertical QoS mapping strategies. On the other hand, DVB‐S2/RCS satellite standard is considered the driving technology to integrate satellite with terrestrial infrastructure and provide up‐to‐date services. This paper focuses on the integration of ETSI BSM architecture and DVB‐RCS technology, by analysing the adaptations needed on real DVB‐RCS terminals to be interoperable with the SI‐SAP interface. To this end, the detailed design of an underlying architecture taking into account required adaptations and new functionalities is proposed. The possible further evolutions of the BSM specification are also highlighted, showing the potential for the development of future devices integrating both DVB‐RCS and ETSI BSM architectures also in view of the recent upgrade to the DVB‐RCS2 standard. The paper also validates the SI‐SAP QoS functionalities and proves the performance benefits in terms of QoS and quality of experience of Web‐browsing by means of a satellite emulator developed fors this aim. Copyright © 2015 John Wiley & Sons, Ltd.     

Cross‐layer packet scheduler for QoS support over Digital Video Broadcasting‐Second Generation broadband satellite systems

This article presents a cross‐layer packet scheduler to provide end‐to‐end QoS guarantees for Digital Video Broadcasting‐Second Generation (DVB‐S2) broadband satellite systems. The scheduler design is based on a cross‐layer mechanism defined between the physical and the network layer. It includes an algorithm to guarantee the required QoS specifications established in the service level agreement. The algorithm calculation depends basically on two parameters: the available bandwidth present in a DVB‐S2 satellite link and the QoS requirements of each traffic class defined by the satellite operator. The cross‐layer scheduler's operation is demonstrated using the NS‐2 simulator tool. The results show that the proposed mechanism maximizes the bandwidth utilization while enforcing the priority level of each service class when an extreme reduction of bandwidth caused by rain events is experienced. Copyright © 2012 John Wiley & Sons, Ltd.     

Profit‐based exclusive‐or coding algorithm for data retransmission in DVB‐H with a recovery network

The digital video broadcasting‐handheld (DVB‐H) standard is developed by European Telecommunications Standards Institute to broadcast digital videos to handheld devices, but data loss is a critical issue due to the broadcast behavior. On the other hand, DVB‐Internet protocol datacasting (DVB‐IPDC) integrates DVB‐H with an Internet protocol‐based wireless network to provide bidirectional communication. We adopt this wireless network to deal with data retransmission and call it a recovery network. The paper argues that network coding can improve retransmission efficiency of the recovery network because DVB‐H packet loss often exhibits high correlation. In addition, DVB‐H packets may be heterogeneous in the sense that they have different importance. According to these two arguments, the paper considers that DVB‐H packets are associated with different profit depending on their importance and proposes an α‐maximum profit network coding problem. It asks the base station in the recovery network to use no more than α coded packets for handheld devices to retrieve the lost DVB‐H packets such that the overall profit is the maximum. An efficient exclusive‐or coding scheme, namely the profit‐based exclusive‐or network coding (PEN) algorithm, is proposed to solve this problem. Extensive simulation results also verify the effectiveness of the PEN algorithm. Copyright © 2014 John Wiley & Sons, Ltd.     

Dynamic resource allocation for DVB‐RCS networks

To provide high‐speed multimedia services using the digital video broadcasting‐return channel satellite (DVB‐RCS) standard, it is imperative to efficiently assign timeslots according to user demands and dynamically take into account the variations of the propagation conditions. In satellite networks operating above 10 GHz, rain fading constitutes the dominant factor deteriorating the quality of service. In this paper, a novel two‐phase resource allocation scheme for a DVB‐RCS compliant satellite network is proposed. The scheme operates in two phases, the resource calculation and the resource assignment. In the resource calculation phase, based on a dynamic channel model, an efficient algorithm is presented to determine the superframe design that maximizes system throughput. In the resource assignment phase, a novel Hybrid Bin‐packing algorithm is introduced maximizing the utilization of the multi‐frequency time division multiple access frame. The proposed algorithm has been compared with existing schemes exhibiting significantly better results with regard to overall system throughput. Copyright © 2008 John Wiley & Sons, Ltd.     

Transport layer enhancements on a satellite‐based mobile broadband system for high‐speed trains

The great diffusion of wireless portable and handheld devices, along with the growing availability of applications on the Internet, led to a significant increase in the demand of access. Users require to continue business or private activities when moving, with performance at least comparable with that experienced over fixed networks. A very interesting scenario encompasses broadband and uninterrupted access over high‐speed trains. Developments of new telecommunication standards as well as innovative network architectures give the potential to fully match the aforementioned requirements. Nevertheless, there is a significant number of issues, especially related to system integration, mobility management, and propagation channel conditions, that need a careful analysis with the aim to support the design of real systems. This paper deals with this challenging scenario proposing a satellite‐based architecture in which DVB‐S2 and DVB‐RCS standards, MIPv6 at layer 3 (for handover management), and an enhanced TCP version at layer 4, named TCP Noordwijk, allow to achieve good performance. An NS‐2 enhanced simulator has supported the whole analysis. Results show the effectiveness of the proposed scheme against different modulation and coding configurations and compared with a selected set of TCP‐enhanced versions. Copyright © 2012 John Wiley & Sons, Ltd.     

A request control scheme for data recovery in DVB‐IPDC systems with spatial and temporal packet loss

Recently, digital video broadcasting‐handheld (DVB‐H) and IP datacast over DVB‐H (DVB‐IPDC) have been developed to support broadcasting services. DVB‐H is designed to support digital video broadcast for handheld devices, whereas DVB‐IPDC can integrate with an IP‐relay network to complement the data loss problem in DVB‐H. Assuming that WiMAX networks are adopted to support DVB‐IPDC, this paper points out two critical problems: group packet loss (GPL) and broadcast data handover (BDH). GPL occurs when there is a burst of retransmission requests for the same pieces of data with high spatial or temporal correlation. BDH happens when some devices that made the above requests handover to new serving cells. To solve these problems, we propose lazy wait and group acknowledgement schemes to alleviate duplicate requests by exploiting their spatial and temporal correlations. This not only reduces the requests submitted by neighboring devices in both space and time domains but also avoids handovering devices from sending duplicate requests in new cells. Through mathematical analysis, we show how to adaptively adjust the timers of lazy wait and group acknowledgement based on channel quality. Simulation results prove that our schemes can efficiently reduce retransmission requests and retransmission packets, thus alleviating congestion in the IP‐relay network. Copyright © 2011 John Wiley & Sons, Ltd.     

Dynamic satellite system QoS architecture integrated with IP Multimedia Subsystem core network

Convergence is one of the most important challenges for Next Generation Networks (NGN). This includes service convergence as well as fixed‐mobile convergence. The integration of satellite telecommunication system into NGN is a key to increasing the coverage of future networks and opening satellite access networks to a wider range of terrestrial solutions. Digital Video Broadcast (DVB) Return Channel via Satellite system (DVB‐RCS) and its evolution (DVB‐RCS2) are widely used European standards that are specified for broadband satellite systems using dynamic capacity assignment and multifrequency TDMA. This paper introduces a new QoS architecture derived from terrestrial IP Multimedia Subsystem solutions to provide advanced end‐to‐end QoS support, and defines cross‐layer optimization paths suited to the satellite context and in particular using DVB standards. Copyright © 2014 John Wiley & Sons, Ltd.     

Adaptive coding and modulation for satellite broadband networks: From theory to practice

This paper presents the detailed design and the key system performance results of a comprehensive laboratory demonstrator for a broadband Ka‐band multi‐beam satellite system exploiting the new DVB‐S2 standard with adaptive coding and modulation (ACM). This complete demonstrator allows in‐depth verification and optimization of the ACM techniques applied to large satellite broadband networks, as well as complementing and confirming the more theoretical or simulation‐based findings published so far. It is demonstrated that few ACM configurations (in terms of modulation and coding) are able to efficiently cope with a typical Ka‐band multi‐beam satellite system with negligible capacity loss. It is also demonstrated that the exploitation of ACM thresholds with hysteresis represents the most reliable way to adapt the physical layer configuration to the spatial and time variability of the channel conditions while avoiding too many physical layer configuration changes. Simple ACM adaptation techniques, readily implementable over large‐scale networks, are shown to perform very well, fulfilling the target packet‐error rate requirements even in the presence of deep fading conditions. The impact of carrier phase noise and satellite nonlinearity has also been measured. Copyright © 2009 John Wiley & Sons, Ltd.     

Digital video broadcasting over satellite (DVB‐S): a system for broadcasting and contribution applications

The general system concepts for digital television transmission and broadcasting by satellite, developed within the European digital video broadcasting (DVB) Project and standardized by ETSI are described. The system (EN 300 421) is designed to provide direct‐to‐home (DTH) multi‐programme TV services in the BSS and FSS bands and is addressed to consumer integrated receiver decoders (IRDs), as well as collective antenna systems (SMATV) and cable television head‐end stations, with a likelihood of remodulation. The system operational modes have been extended in 1998 (EN 301 210) to cover also ‘contribution’ applications by satellite, such as conveying vision and sound material between TV studios, or from remote locations directly to the broadcaster's premises through light and portable up‐link terminal digital satellite news gathering (DSNG). The exploitation of the multiplex flexibility allows the use of the transmission capacity for a variety of TV service configurations. The use of flexible and advanced error protection techniques, based on the concatenation of Reed‐Solomon and convolutional codes (with Viterbi decoding), allows optimum adaptation to different satellite transponder characteristics, i.e. bandwidth and power, providing high service quality and availability with small receiving antennas (DTH applications) or transmitting terminals (DSNG applications). Copyright © 2000 John Wiley & Sons, Ltd.     

On the fairness of return channel capacity allocation in DVB‐RCS‐based satellite networks

Broadband satellite access (BSA) systems can form an alternative path for the provision of Internet access in areas with poor network infrastructure. The DVB‐RCS standard introduced the specifications of an interaction channel for two‐way BSA networks. In this study, a new dynamic scheduling strategy for the interaction channel of GEO satellite networks is proposed, evaluated and compared with a typical Round Robin scheme. The main idea of the proposed strategy is to change, prior to each allocation, the sequence according to which bandwidth is assigned to the satellite terminals. The new sequence is fully specified by a set of fairness indices, each one related to a unique terminal and updated after each allocation. Along with the examined scheduling strategies, two capacity request calculation techniques found in the literature are also evaluated and compared through a series of simulations. Copyright © 2010 John Wiley & Sons, Ltd.     

Performance evaluation of TCP‐based applications over DVB‐RCS DAMA schemes

Transmission Control Protocol (TCP) performance over Digital Video Broadcasting—Return Channel via Satellite (DVB‐RCS) standard is greatly affected by the total delay, which is mainly due to two components, propagation delay and access delay. Both are significant because they are dependent on the long propagation path of the satellite link. The former is intrinsic and due to radio wave propagation over the satellite channel for both TCP packets and acknowledgements. It is regulated by the control loop that governs TCP. The latter is due to the control loop that governs the demand assignment multiple access (DAMA) signalling exchange between satellite terminals and the network control center, necessary to manage return link resources. DAMA is adopted in DVB‐RCS standard to achieve flexible and efficient use of the shared resources. Therefore, performance of TCP over DVB‐RCS may degrade due to the exploitation of two nested control loops also depending on both the selected DAMA algorithm and the traffic profile. This paper analyses the impact of basic DAMA implementation on TCP‐based applications over a DVB‐RCS link for a large set of study cases. To provide a detailed overview of TCP performance in DVB‐RCS environment, the analysis includes both theoretical approach and simulation campaign. Copyright © 2009 John Wiley & Sons, Ltd.     

Error repair for broadcast transmissions in DVB‐H systems

People travelling in public transportation vehicles are foreseen to be a relevant use case of future Digital Video Broadcast—Handhelds (DVB‐H) systems. However, it is also one of the critical user cases, since, besides the vehicle penetration loss, the received signal quality is strongly affected by the high mobility of the users, which is accompanied by temporary shadowing and fast fading. On the other hand, mobility can be also beneficial thanks to the bursty character of DVB‐H transmissions, as additional repair data can be sent in the time intervals between original service bursts in order to hide the coverage discontinuities from the users' perception. In this way, users which miss the original transmission have more chances to receive the information correctly. By managing the amount of repair data the network operator can trade system capacity and network latency for improved vehicular user satisfaction in a DVB‐H network with imperfect coverage of the service area (as perceived by the vehicular users). To illustrate the potential of this approach, we evaluate the mentioned trade‐off in a DVB‐H system dimensioned for pedestrian outdoor users, for both streaming and filecasting services. To enable an easy and efficient implementation of the repair mechanisms, we adopt application layer forward error correction (FEC), as it can provide a multi‐burst protection of the transmission. Copyright © 2008 John Wiley & Sons, Ltd.     

Future technologies for very high throughput satellite systems

In this paper, we investigate the possible satellite's role and technical solutions required for providing broadband services complementing the terrestrial fifth generation wireless standards. First, we review the satellite networks use cases, services, and system requirements. Then we investigate the satellite potential purpose for broadband service provision and the associated challenges with focus on the system and space/ground technological aspects. Different architectural satellite network solutions are illustrated jointly with the key system design trade‐offs. Particular emphasis is dedicated to the payload architecture. Finally, we illustrate the space and ground segment technologies enabling the successful satellite contribution to broadband services provision.     

Multiservice platforms for data services

The potential for broadband and data services is large and continues to expand for the foreseeable future. Consideration of the cost-effective delivery and support of both new, advanced services, as well as existing services, has led to the driver for multiservice platforms (MSPs). The cost effectiveness results from the MSP potential to share network bandwidth between services, offer a potential simplification of the operational support systems (OSS), and enable new service features and functions. A generic ATM-based MSP is described in this paper where issues of service support, service interworking, operations and maintenance, and network architecture are discussed. The paper is intended as a tutorial on the concepts.