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All posts by Squire Tech

Efficient dynamic authentication for mobile satellite communication systems without verification table

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SUMMARY

The mobile satellite system is an important wireless communication system widely used nowadays. The issue of protecting the transmission security in low-earth-orbit satellite networks thus becomes more and more critical. It is known that several authentication schemes for satellite communication systems have been proposed to deal with the issue. However, previous protocols either employ complicated public key computation or have to maintain a verification table. In this paper, the author will introduce a new dynamic authentication protocol for mobile satellite communication systems without using a verification table.

Lin H.-Y. “Efficient dynamic authentication for mobile satellite communication systems without verification table” Wiley, 8 September 2014. Web. 8 September 2014.

http://onlinelibrary.wiley.com/doi/10.1002/sat.1088/abstract

Early detection and rejection probability-based congestion control scheme for deep space networks

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Summary

Deep Space Networks (DSNs) are a class of DTNs. In such networks, owing to limited radio range and node mobility, end-to-end paths between source and destination nodes are not available. Messages are relayed by store-and-forward strategy and may be buffered for long periods before being forwarded to the next hop. Therefore, the buffer of message carriers may overflow, and congestion follows. To address this issue, this paper proposes an early detection and rejection probability-based congestion control algorithm, named ERBA, in which every intermediate node estimates rejection probability when a new message arrives and refuses to receive the message with the rejection probability, so as to avoid congestion. To validate its effectiveness, ERBA is merged into static routing (SR) and dynamic routing (DR). SR and DR are classical routing algorithms for DSNs. The simulation results show that when working with ERBA, the routing overhead of SR and DR decreases rapidly.

Y Jiang G. Shen Y. and Chen J. “Early detection and rejection probability-based congestion control scheme for deep space networks” Wiley, 5 September 2014. Web. 5 September 2014.

http://onlinelibrary.wiley.com/doi/10.1002/sat.1094/abstract

Satellite interference evaluation: joint effect of modeling earth station locations and earth station antenna sidelobe gains as random variables

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SUMMARY

When several satellite communication systems share the same frequency band, each system operates under the aggregate interference generated by the others. In this interfering environment, interference calculation procedures in which worst-case situations and simplifying assumptions are considered are commonly used. Given that the geostationary satellite orbit and the frequency spectrum are limited resources, it is important to consider alternatives that lead to a more precise interference evaluation. One of these alternatives is the use of a probabilistic methodology, in which some of the parameters involved are modeled as random variables. This work considers the specific case in which the earth station geographic locations and the sidelobe gains of their antennas are modeled as random.

Tamo, A. and Fortes, J. M. P. “Satellite interference evaluation: joint effect of modeling earth station locations and earth station antenna sidelobe gains as random variables” Wiley, 3 September 2014. Web. 3 September 2014.

http://onlinelibrary.wiley.com/doi/10.1002/sat.1089/abstract

QoS provisioning by power control for video communication via satellite links

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SUMMARY

Video transmissions over satellite links are sensitive to signal fades because of rain, especially in the tropics. We performed a video-streaming experiment over a satellite link for 24 days distributed over 1 year to investigate the effects of rain fade. Based on the measurements, models for the relationships between rainfall rate, power level, packet loss, and video quality are proposed. Furthermore, for both uplink and downlink channel, an adaptive closed loop power control algorithm, with a Proportional–Integral–Derivative controller is designed. This is used for the mitigation of the rain-induced attenuation in order to guarantee a certain level of Quality of Service and Quality of Experience.

Ma T., Lee Y. H., Winkler S. and Ma M. “QoS provisioning by power control for video communication via satellite links” Wiley, 1 September 2014. Web. 2 September 2014.

http://onlinelibrary.wiley.com/doi/10.1002/sat.1087/abstract

Welcome to our Satellite Blog

By | Industry News, Satellite Blog | No Comments

In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon. The world’s first artificial satellite, the Sputnik 1, was launched by the Soviet Union in 1957. Since then, thousands of satellites have been launched into orbit around the Earth. Read More

Rain granularity effects on bandwidth demand for faded DVB-RCS systems

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Broadband satellite communication networks, operating at Ka band and above, play a vital role in today’s worldwide telecommunication infrastructure. The problem, however, is that rain can be the most dominant impairment factor for radio propagation above 10 GHz. This paper studies bandwidth and time slot allocation problem for rain faded DVB-RCS satellite networks. We investigate how using finer rain granularity can improve bandwidth utilization in DVB-RCS return links.

Al-Mosawi, M., Khusainov, R. and Gremont, B. “Rain granularity effects on bandwidth demand for faded DVB-RCS systems” Wiley, 25 August 2014. Web. 26 August 2014.

http://onlinelibrary.wiley.com/doi/10.1002/sat.1085/abstract

Intelsat Napa Teleport in Epicenter of 6.0 Earthquake [Industry update]

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The earthquake lies within a 70-km-wide (44 miles) set of major faults of the San Andreas Fault system that forms the boundary between the Pacific and North American tectonic plates. The persistent northwestward movement of the Pacific plate relative to North America primarily causes right-lateral slip across the major faults, but also causes deformation between the major faults. Read More