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Satellites are expected to play an essential role in providing broadband and multicast services to regions that cannot be economically reached by terrestrial networks, in particular the more remote regions of Europe and the rest of the world. Security can be a problem for such global services. Security of multicast data is becoming an important issue to operators and users of satellite networks. This paper presents a proposed secure multicast architecture that fits well into the ETSI BSM overall architectural concepts. Multicast service scenarios with detailed security architecture are presented using the BSM standard interface between satellite dependent and independent layers. This architecture accommodates link and network layer security (Internet) security systems and interworking with non- satellite entities such as AAA, PEPs and COPs entities. [ABSTRACT FROM AUTHOR]

The last years have seen a solid interest in Voice over IP (VoIP), also referred to as Internet or IP Telephony. The interest in this kind of communications is fueled by the multiple advantages that VoIP holds. Nonetheless, several strides remain to be made in order for VoIP systems to be on a par with the well engineered Public Switched Telephone Network (PSTN). From the network's viewpoint, one major downside of this application is the relatively high size of the IP/UDP/RTP headers compared to the packet's payload, which translates in inefficient bandwidth utilization. This work intends to assess the performance of two well-known header compression schemes that is Compressed RTP (CRTP) and Enhanced CRTP, over satellite links. For the needs of this comparison a software platform was implemented which models the behavior of the satellite channel and permits the evaluation of different header compression schemes on real traffic. [ABSTRACT FROM AUTHOR]

Satellite communications based on geo-synchronous satellites are characterized by a large delay, and high cost of resources. VoIP applications over satellite networks must thus be handled very carefully so as to provide quality of service, as expected from voice calls, namely: secure resources for a call throughout its duration, regardless of other calls and other data traffic being present in the system. Furthermore, jitter and delay must be kept to a minimum while maintaining as high satellite resource exploitation efficient. These subjects are well treated in the previous generation of satellite telephony products (Also referred to as ‘Native telephony'). Basically, the circuit switching approach dominated these solutions, with specific solutions applied to both the access level and the application level. The media itself, derived from the requirement of bandwidth efficiency, used the very same CODECs used for VoIP such as G.723 and G.729. The native telephony solution is jitter free, minimal delay, total QoS (regardless of other calls or data) and extremely efficient. The purpose of the current work was to capitalize on the existing infrastructure and its benefits and to port them to the VoIP environment. The approach described herein was implemented in Gilat's SkyEdgeTM VSAT (Very Small Aperture Terminal) product and is operational for about 2 years. [ABSTRACT FROM AUTHOR]

The MPEG-2 standard supports a range of transmission methods for a range of services. This document provides a security solution at the link layer using the Unidirectional Lightweight Encapsulation. It describes the SATIPSec key management protocol and its adaptation for DVB-RCS networks to provide security at the ULE level. Also the forward link signalling risks are analyzed and a possible security solution has been proposed. [ABSTRACT FROM AUTHOR]

SATSIX contributes to enhance the positioning of satellite access systems in the Broadband Access Market and capitalises the development and deployment of NGN and IPv6 through satellite. Through live demonstrators, SATSIX will prove the capability of the satellite to provide affordable services to a large customer range. The SATSIX Work package/Activity 3200 aims at validating this concept, demonstrating its feasibility by means of demonstration scenarios. [ABSTRACT FROM AUTHOR]

Emulation is a cost effective and efficient tool to perform performances evaluation and innovative access and network techniques validation. Its ability to interconnect real equipments with real applications provides excellent demonstrations means. The main problem is to overcome the emulation weakness which is the accuracy of the model reproducing the systems to be evaluated. Owing to its modular design and implementation, the PLATINE satellite emulation platform, presented in this paper, is able to emulate a complete DVB-RCS (Digital Video Broadcasting — Return Channel via Satellite)- DVB-S2 (Digital Video Broadcasting — Second) system in a realistic and flexible way. It is possible to configure the platform to emulate a transparent DVB-RCS system dimensioned around a single Hub, or to emulate a system using a regenerative satellite with an onboard switching matrix. Different DVB-RCS protocol stacks are implemented, and the adaptive physical layer is emulated in real time thanks to precalculated DRA schemes and MODCOD files. A DiffServ-like QoS Architecture that couples MAC and IP-Layer QoS mechanisms and Layer 2 security framework are currently under development. At the network side, IPv4 and IPv6 are fully supported as well as IPv6 mobility and dynamic multicast. In this paper, we mainly focus on the emulation platform and the tools developed to help the performance analysis of the emulated system. [ABSTRACT FROM AUTHOR]

As one of the key elements in an IPv6 supported DVB-RCS satellite network, the multicast architecture design is facing the challenges of interworking between the IPv6 multicast protocols and the satellite signaling while efficiently using the satellite bandwidth. How to enable the multicast group management functions for satellite end users with and without direct IPv6 MLD router support and how to translate the IP multicast routing protocol messages to the satellite lower layer signaling to establish the satellite channels between two spot beams need to be answered. With the regenerating satellite space segment, dynamic multicast routing is possible and making an efficient use of the satellite bandwidth has to be considered. This paper presents the SATSIX approaches of a multicast architecture involving both the IP multicast and the C2P protocols to address and solve these questions. [ABSTRACT FROM AUTHOR]

This paper deals with the support of IPv6 for mobile user groups using the scenario of passengers in an aircraft connected via a satellite link to ground Internet. Several solutions are discussed to support user laptops having IPv6. The peculiarity of the scenario lies in the fact that satellite modems usually offer single IPv4 addresses only. We address IPv6 over IPv4 tunnelling and Network Address and Port Translation (NAPT) with dual stack routers as possible solutions. The NAPT solution is optimized to save overhead over the satellite link, and required signalling to allow ground-to-air traffic is addressed. Finally, a performance estimation is given. [ABSTRACT FROM AUTHOR]

This paper describes the recent results of the work in the ETSI BSM standardisation group and its relationship to Satsix. The ETSI BSM WG focuses on IP-based networks and the associated needs for standardisation when satellites are integrated within them. The BSM group comprises major organisations from the satellite world and therefore its outputs represent a consensus of the most important techniques and solutions relevant in this sphere of activity. SatSix has had an important influence on the standards produced through the many contributions made and resulting technical discussions. The BSM protocol architecture used throughout the standards produced is characterised by the separation between common Satellite-Independent (SI) protocol layers and alternative lower Satellite-Dependent (SD) layers. [ABSTRACT FROM AUTHOR]

This paper presents the architecture developed in Satsix project in order to improve the current QoS level in satellite/terrestrial networks. The dynamic QoS support is one of the major achievement of SATSIX in the QoS area, with the extension of the QoS agent/server architecture proposed in the previous SATIP6 project. This QoS architecture is based on DiffServ architecture, and it has been proposed aiming to tackle different QoS level sessions. [ABSTRACT FROM AUTHOR]

AMAZONAS satellite, launched in the summer of 2004, includes AMERHIS payload, being the first regenerative system using DVB-RCS/DVB-S standards to inter-connect four coverage areas located in Europe and America, in only one single satellite hop. In the frame of SATLIFE, the different regenerative satellite terminals have been enhanced, including standard technologies to optimize performance through the satellite link. Management Station upgrade is in line with these RCST improvements, supporting new video terminals and multicast routing apart from broadcast. Using the new developments in the prototypes, different multimedia services and applications have been integrated over the regenerative satellite network. Index terms: Digital TV, DVB-RCS, IP, Multicast, Multimedia, Network, OBP, Regenerative, Satellite, Video Broadcasting. [ABSTRACT FROM AUTHOR]

Digital satellite broadcasting, primarily targeted to unidirectional services, soon expanded to the interactive domain, utilising uplink technologies such as DVB-RCS. In this context, due to their wide and uniform coverage, satellites can provide an ideal medium for the provision of triple play services (voice, video and data) to remote areas not covered by terrestrial infrastructures. This paper discusses and demonstrates the delivery of triple play services over a fully functional platform utilising the second-generation satellite broadcasting technology (DVB-S2) for the downlink combined with DVB-RCS for the uplink. [ABSTRACT FROM AUTHOR]

SatNEx aims to rectify the fragmentation in satellite communications research by bringing together Europe's leading academic institutions and research organisations in a cohesive and durable way. The resultant pan-European network provides a collective grouping of expertise and state-of-the-art laboratory facilities that would otherwise remain dispersed throughout Europe. [ABSTRACT FROM AUTHOR]

Aiming to provide low-cost universal broadband access, this paper describes the strategy that supports the integration of hybrid satellite and WiMAX, based on the network architecture proposed in the IST Satsix project. In this context, WiMAX networks can be used as wireless local loops integrated with a satellite network, lowering the cost of the broadband internet connections and providing a universal access to rural and marine areas. The paper presents the problems concerning the interworking between DVB-RCS and WiMAX technologies and the solutions adopted in the SatSix research project, partially funded by European Commission within the Information Society Technologies (IST) 6th Framework Programme. [ABSTRACT FROM AUTHOR]

Broadband satellite will play an important role to provide universal broadband access for the users. In order to lower the cost, the next-generation satellite systems should support IPv6 and seamlessly integrate with terrestrial networks, including wireless local loops. Based on the studies on the requirements and design constraints, in this paper, a novel network architecture has been proposed as a potential solution to the above problems. The proposed network architecture supports both transparent and regenerative topologies and can seamlessly interworking with WLL. It also integrates QoS, multicast, security, and mobility functions to support a range of transport requirements. How to apply this network architecture to support three different scenarios, namely corporate application scenario, residential application scenario and collective access terminal scenario, are also described. [ABSTRACT FROM AUTHOR]

The EU-funded IST FP6 Satellite-based communications systems within IPv6 (SATSIX) project aims to study, implement and validate innovative concepts and cost-effective solutions for broadband satellite systems relying on DVB-RCS/S2 standards and services. This paper presents a description of the Radio Resource Management protocols and algorithms developed so far. The major objective is to propose efficient resource management for satellite systems using Fade Mitigation Techniques to face deep fading caused by the attenuation and scintillation effects of atmospheric gas, clouds, rain and melting. The procedures will be simulated as well as tested and evaluated via a satellite emulation testbed developed within the project. [ABSTRACT FROM AUTHOR]

This paper introduces a cross-layer approach for improving QoS guaranties to interactive multimedia applications over an efficient satellite access assignment scheme (on-demand). It particularly focuses on the communication opening which represents the weakness of on-demand capacity allocation in the satellite context (due to significant delays). It finally presents experimental results of the various proposed enhancements. [ABSTRACT FROM AUTHOR]

As wireless and satellite networks become widely used, new ways to think communication can be envisaged. In particular, a greater degree of connectivity is almost becoming a necessity for the users on the go, being connected whatever their locations are. Different definitions of mobility are emerging, and in SATSIX three mobility scenarios are defined, namely discrete mobility, continuous mobility and seamless mobility. Next, two mobility contexts; macro-mobility and micromobility, according to network hierarchy have been considered. To improve the mobility management, and reducing signaling overhead and handover delay when using MIPv6, the enhancement protocols HMIPV6, FMIPv6 and the combination FHMIPv6 are investigated. Application mobility is analyzed as a complement to network layer mobility. The project also addresses the impacts on several others key networking functions like multicast, QoS and PEP. [ABSTRACT FROM AUTHOR]

Internet services using satellites for high-speed trains are being widely studied these days. The major drawback of satellite networks is that antennas on the trains can not receive signals from the satellites in train stations. To solve this problem, IP handover to terrestrial wireless networks in the stations is considered. However, due to long disconnection time of layer 2 and layer 3, the performance of current IP handover schemes is not good in this handover case. In this paper, we propose a new IP handover scheme between a geo-satellite network and a terrestrial wireless LAN network for high-speed trains. Through simulations, we show that proposed handover scheme greatly reduces overall handover latency and increases TCP throughputs. [ABSTRACT FROM AUTHOR]

Satellite platforms that already provide broadband access for Internet/Intranet (IPv4) and PSTN/ ISDN terrestrial networks are evolving towards the convergence with other network access technologies as WiFi and WiMax searching for mobility, QoS and IPv6 protocol evolution. This paper presents the benefits of the Next Generation Broadband Satellite Multimedia Systems and Network architecture future enhancements in the frame of EC-funded IST FP6 SATSIX (Satellitebased communications systems within IPv6) project. [ABSTRACT FROM AUTHOR]

This paper offers an overview in the new developments carried out and services offered thanks to SATLIFE project [1]. Based on the AmerHis system [2], SATLIFE [3] has been working in the improvement of the new AmerHis capabilities, looking for a decrease in costs and the provision of new services not yet offered over a regenerative DVB-RCS platform. Satlife concept is introduced, and an analysis of Amerhis/Ibis service enhancements is carried out, together with a deep overview of the new services and functionalities developed. In the phase of real trials, Satlife is testing all the features developed over these two last years. [ABSTRACT FROM AUTHOR]

The EU-funded IST FP6 Project Satellite-based communications systems within IPv6 (SATSIX) is implementing and validating innovative concepts and cost-effective solutions for broadband satellite systems that build upon the DVB-RCS/S2 standards and services. It promotes the introduction of IPv6 into satellite-based communications systems and the development of hybrid networks that combine the use of satellite with wireless access technologies. The main objective is to lower the cost of broadband satellite access, through the development of new satellite access techniques and the integration of wireless local loops (WiFi and WiMax). Simulations, test beds and trial networks will show how satellite broadband access can be integrated into Next Generation Networks, based on IPv6, to support new multimedia applications. [ABSTRACT FROM AUTHOR]