Effective extensions of Internet in hybrid satellite-terrestrial networks (original) (raw)
Related papers
Implementation and Evaluation of TCP Enhancements over Satellite Links
2006
Internet over satellite is an emerging facet of communications enabling users to have access to the Internet over high speed satellite links. However, new requirements should be satisfied by the involved protocols in order to fully utilize the available network resources. This paper discusses the possible mitigations that can be applied to the Transmission Control Protocol over satellite links. Furthermore, we study the performance of the TCP enhancements we implemented in a simulated satellite environment.
An architecture for Internet service via broadband satellite networks
International Journal of Satellite Communications, 2001
High bandwidth satellites hold out the promise of a rapidly deployable communications infrastructure with a natural support for mobility. However, the Transmission Control Protocol, widely used in the Internet, performs poorly over satellite links, and this presents an obstacle to the deployment of such systems. We present an architecture that overcomes these problems and provides an approach to building complex heterogeneous networks from simple units. We also present some results from our initial implementation, which uses TCP connection splitting to improve TCP performance over satellite links.
Internet service via broadband satellite networks
Multimedia Systems and Applications, 1999
The demand for Internet bandwidth has grown rapidly in the past few years. A new generation of broadband satellite constellations promise to provide high speed Internet connectivity to areas not served by optical fiber, cable or other high speed terrestrial connections. However, using satellite links to supply high bandwidth has been difficult due to problems with inefficient performance of the Internet's TCP/IP protocol suite over satellite. We describe an architecture for improving the performance of TCP/IP protocols over heterogeneous network environments, especially networks containing satellite links. The end-to-end connection is split into segments, and the protocol on the satellite segment is optimized for the satellite link characteristics. TCP congestion control mechanisms are maintained on each segment, with some coupling between the segments to produce the effect of end-to-end TCP flow control. We have implemented this design and present results showing that using such gateways can improve throughput for individual connections by a large factor over paths containing a satellite link.
Performance Modelling of TCP Enhancements in Terrestrial–Satellite Hybrid Networks
IEEE/ACM Transactions on Networking, 2006
In this paper, we focus on the performance of TCP enhancements for a hybrid terrestrialsatellite network. While a large body of literature exists regarding modeling TCP performance for the wired Internet, and recently over a single-hop wireless link, the literature is very sparse on TCP analysis over a hybrid wired-wireless (multi-hop) path. We seek to make a contribution to this problem (where the wireless segment is a satellite uplink) by deriving analytical estimates of TCP throughput for two widely deployed approaches-TCP splitting and E2E(End-to-End) TCP with link layer support as a function of key parameters such as terrestrial/satellite propagation delay, segment loss rate and buffer size. Our analysis is supported by simulations; throughput comparisons indicate superiority of TCP splitting over E2E scheme in most cases. However, in situations where end-to-end delay is dominated Contact Author: Sumit Roy, (Phone/
SaTPEP: A TCP Performance Enhancing Proxy for Satellite Links
Lecture Notes in Computer Science, 2002
Satellite link characteristics cause reduced performance in TCP data transfers. In this paper we present SaTPEP, a TCP Performance Enhancing Proxy which attempts to improve TCP performance by performing connection splitting. SaTPEP monitors the satellite link utilization, and assigns to connections window values that reflect the available bandwidth. Loss recovery is based on Negative Acknowledgements. The performance of SaTPEP is investigated in terms of goodput and fairness, through a series of simulation experiments. Results obtained in these experiments, show significant performance improvement in presence of available bandwidth and at high error rates. 1 1 This work is partially supported by OTE S.A. R&D laboratories
On TCP performance over asymmetric satellite links with real-time constraints
Computer Communications, 2007
Real-time transmission over asymmetric satellite IP links is challenging, since satellite systems commonly exhibit long propagation delays, while bandwidth asymmetry often enforces a variable and infrequent rate of acknowledgment packets (ACKs) across the upstream channel with several undesirable implications. In this context, we formulate an analytical model in order to quantify the impact of satellite systems and link asymmetry on TCP performance and real-time delivery. We emphasize on the effects of asymmetric links, and especially on the implications that cause interruptions in the sending rate, and eventually disturb smooth delivery. Since TCP performance is in part throttled by the rate of arriving ACKs, we additionally investigate the impact of delayed ACKs. Although delayed ACKs occasionally diminish the transmission rate, we uncover notable gains in terms of smoothness and real-time delivery. Furthermore, we demonstrate conclusive performance studies tackling the supportive role of selective acknowledgments (SACK) and the effect of varying bit error rates. Our simulation results illustrate that most existing end-to-end solutions do not comply with the stringent Quality of Service (QoS) provisions of time-sensitive applications, resulting in ineffective bandwidth utilization and varying delays in data delivery. Finally, with the absence of a satellite-optimized TCP implementation for real-time transmission, we identify the most prominent end-to-end solutions that manage to alleviate most of the impairments induced by asymmetric satellite links, sustaining a relatively smooth transmission rate.
TCP-Peach: a new congestion control scheme for satellite IP networks
IEEE/ACM Transactions on Networking, 2001
Current TCP protocols have lower throughput performance in satellite networks mainly due to the effects of long propagation delays and high link error rates. In this paper, a new congestion control scheme called TCP-Peach is introduced for satellite networks. TCP-Peach is composed of two new algorithms, namely Sudden Start and Rapid Recovery, as well as the two traditional TCP algorithms, Congestion Avoidance and Fast Retransmit. The new algorithms are based on the novel concept of using dummy segments to probe the availability of network resources without carrying any new information to the sender. Dummy segments are treated as low-priority segments and accordingly they do not effect the delivery of actual data traffic. Simulation experiments show that TCP-Peach outperforms other TCP schemes for satellite networks in terms of goodput. It also provides a fair share of network resources.
International Journal of Communication Systems, 2007
In this article, performance of delay-sensitive traffic in multi-layered satellite Internet Protocol (IP) networks with on-board processing (OBP) capability is investigated. With OBP, a satellite can process the received data, and according to the nature of application, it can decide on the transmission properties. First, we present a concise overview of relevant aspects of satellite networks to delay-sensitive traffic and routing. Then, in order to improve the system performance for delay-sensitive traffic, specifically Voice over Internet Protocol (VoIP), a novel adaptive routing mechanism in two-layered satellite network considering the network's real-time information is introduced and evaluated. Adaptive Routing Protocol for Quality of Service (ARPQ) utilizes OBP and avoids congestion by distributing traffic load between medium-Earth orbit and low-Earth orbit layers. We utilize a prioritized queueing policy to satisfy qualityof-service (QoS) requirements of delay-sensitive applications while evading non-real-time traffic suffer low performance level. The simulation results verify that multi-layered satellite networks with OBP capabilities and QoS mechanisms are essential for feasibility of packet-based high-quality delay-sensitive services which are expected to be the vital components of next-generation communications networks. offer mobile and fixed services with high bandwidth and global coverage which make their usage quite attractive for communications. Combining these two technologies creates a synergy and results in state of the art and efficient systems. New generation satellites, rather than oldfashioned 'bent pipes', can achieve on-board processing (OBP) resulting in faster service and higher performance at the cost and complexity trade off. With the deployment of thirdgeneration (3G) and advent of fourth-generation (4G) networks, these capabilities will be crucial for better services and help the implementation of 'ubiquitous and pervasive communications' concept.