Satellite Access Networks Research Articles

A scalable framework for in IP-oriented terrestrial-GEO satellite networks

The exponential growth of the Internet, the heterogeneity of networks, and the need for QoS maintenance have urged researchers to develop ideas for managing network scalability and end-to-end QoS assurance. In this article, an IP IntServ architecture in the satellite access network is combined with a scalable IP DiffServ-like architecture in the terrestrial core network. The proposed architecture aims at guaranteeing fine-grained bandwidth control in the satellite access network and stateless scalability in the core network, by exploiting per-aggregate traffic flow control, typical of the aggregate RSVP protocol, and stateless service assurance, typical of the SCORE approach.

Satellite transport protocol handling bit corruption, handoff and limited connectivity

Being both wireless and mobile, low Earth orbiting (LEO) satellite access networks have a unique set of link errors including bit corruption, handoff, and limited connectivity. Unfortunately, most transport protocols are only designed to handle congestion-related errors common in wired networks. This inability to handle multiple kinds of errors results in severe degradation in effective throughput and energy saving, which are relevant metrics for a wireless and mobile environment. A recent study proposed a new transport protocol for satellites called STP that addresses many of the unique problems of satellite networks. There was, however, no explicit attempt to implement a differentiating error control strategy in that protocol. This paper proposes grafting a new probing mechanism in STP to make it more responsive to the prevailing error conditions in the network. The mechanism works by investing some time and transmission effort to determine the cause of error. This overhead is, however, recouped by handsome gains in both the connection's effective throughput and its energy efficiency.

S‐UMTS access network for broadcast and multicast service delivery: the SATIN approach

AbstractThis paper proposes a complete satellite access network solution for multimedia broadcast multicast service (MBMS) delivery based on T‐UMTS standards. First, the benefits of MBMS delivery via satellite (SAT‐MBMS) for both S/T‐UMTS network operators are shown with market and business analysis. A new integrated S/T‐UMTS architecture for MBMS delivery is proposed featuring an intermediate module repeater (IMR) for coverage of urban areas. The architectural options of IMR and terminals are discussed considering the relevant cost and complexity. The IMR propagation channel conditions are investigated and a new propagation channel model is proposed. The potential of advanced coding schemes such as the layered coding technique to tackle the channel variations in broadcast/multicast environment is outlined. The functional and protocol architecture are defined along with the interface between the satellite access network and the UMTS core network. Required modifications on the terrestrial access scheme sub‐layers to support MBMS data are investigated and the relevant logical, transport and physical channels are selected. Based on the channel selection and the point‐to‐multipoint service nature, we define a generic radio resource management (RRM) strategy that takes into account both QoS and GoS requirements. The efficiency of the proposed solutions is evaluated in the presented simulation results, advocating the feasibility of the overall approach. Copyright © 2004 John Wiley & Sons, Ltd.

An IP‐based satellite communication system architecture for interactive multimedia services

AbstractThe paper presents an IP‐based broadband satellite access (BSA) network architecture for interactive multimedia services with an emphasis on the return link (upstream direction). Dynamic capacity allocation (DCA) strategies based on the Combined Free and Demand Assignment Multiple Access (CFDAMA) scheme to support the Digital Video Broadcasting‐Return Channel via Satellite (DVB‐RCS) standard and Differentiated Services (DiffServ) architecture in order to achieve short delay and different QoS requirements are proposed. DCA scheduling algorithms and multiple‐queue user terminal structures are presented. Simulation results on the traffic performance for various traffic loads, types and conditions confirm the effectiveness of the proposed structures. Copyright © 2003 John Wiley & Sons, Ltd.

Design and validation of QoS aware mobile internet access procedures for heterogeneous networks

In this paper, the requirements for personal environments mobility are addressed from terminal and network perspectives. Practical mobility and Quality of Service (QoS) aware solutions are proposed for a heterogeneous network, comprising of satellite and terrestrial access networks connected to an IP core network. The aim, in adopting a heterogeneous environment, is to provide global, seamless service coverage to a specific area, allowing access to services independently of location. An important assumption is that nomadic user terminals attached to a particular segment should be able to exchange information with any other terminal connected to the network. This is to ensure transparency of device technology. Different communication scenarios are investigated in support of IPv4 and IPv6 operating on user platforms and over access segments. The heterogeneous network necessitates the need to perform handover between access segments to enable coverage extension and seamless connectivity. Handover procedures are analyzed, and an approach is presented that enables various operation and segment specific parameters to be taken into account when deciding upon the need to perform handover and in selecting the optimum access segment. In order to ensure transparency of network technology, the need for end-to-end QoS support is discussed, bearing in mind the deployment of both IntServ and DiffServ enabled routers in the core network. Following this, a new admission control scheme, named Gauge&Gate Reservation with Independent Probing (GRIP), is proposed. The paper concludes with a description of a laboratory testbed, which has been developed in order to verify the presented procedures, together with performance measurements of the handover and the GRIP algorithms.

Delay bounds for voice over IP calls transported over satellite access networks

Whether or not voice calls of traditional quality can be supported between two users connected to an IP backbone via satellite access systems depends largely on the mouth-to-ear delay, an important part of which is consumed by the satellite networks themselves. In this paper, a methodology is developed to calculate upper bounds for the latter delay component as a function of the used codec, the experienced packet loss ratio, the echo levels at both sides of the connection and the chosen voice packet size. Illustrations are provided.

IP with QoS guarantees via Geo satellite channels: performance issues

The rapid proliferation of the Internet over recent years has roused the research community's interest id QoS guarantees to IP traffic. The integration of new satellite technologies with terrestrial broadband networks can provide worldwide reachability to a wide range of IP-based multimedia applications and services. Thus, a great deal of research is being conducted to extend IP technology with QoS guarantees to satellite links. The purpose of this article is to contribute to this issue. In fact, the main focus is on the satellite access network of an integrated terrestrial-satellite multimedia platform. In this scenario, effective solutions to transport real-time IP traffic with quality of service (QoS) guarantees are proposed, and their effectiveness is assessed. Real-time IP services with different traffic descriptors and delay requirements are considered, and therefore the best transport solution (in terms of guaranteed quality and efficiency in satellite resource utilization) over permanent or semi-permanent satellite connections is identified.

Protocol architectures for satellite ATM broadband networks

The latest developments and experimentation in asynchronous transfer mode (ATM) technology show that ATM will be a candidate transport mechanism in many private and public multimedia networks. Furthermore, the interest in satellite ATM systems has grown considerably because they can rapidly and economically extend the boundaries of any terrestrial network. Currently, there is a huge increase in the demand for satellite communications operating at the Ka-frequency bands; several different systems have been proposed and are under development worldwide. Two main scenarios for satellite access network protocols are presented in this article. The first one uses ATM cell encapsulation and satellite-specific protocols for establishing and managing a connection, whereas the second one provides a highly integrated solution with the ATM protocol stack and defines a new satellite ATM (S-ATM) protocol layer.