News

Texas Universities Weather Hurricane Ike

2016-02-10T09:52:16+00:00

First the good news: Universities and research institutions in Texas suffered far less damage than some had feared from Hurricane Ike. Now, the bad news: It could take weeks for the University of Texas Medical Branch (UTMB) on the flooded island of Galveston and satellite Texas A&M campuses in the Galveston area to be fully [...]

Texas Universities Weather Hurricane Ike 2016-02-10T09:52:16+00:00

Comparison of measured rain attenuation in the 10.982-GHz band with predictions and sensitivity analysis

2016-02-10T09:52:24+00:00

SUMMARY The campaign to collect rain attenuation data on terrestrial links had commenced in Malaysian tropical climates for almost two decades. The terrestrial data so far collected have been greatly utilized to derive useful statistics for various microwave applications, such as frequency scaling, rain rate conversion factor, 1-min rain rate contour maps, wet antenna losses, [...]

Comparison of measured rain attenuation in the 10.982-GHz band with predictions and sensitivity analysis 2016-02-10T09:52:24+00:00

Exploiting cognitive radios for reliable satellite communications

2016-02-10T09:52:32+00:00

SUMMARY Satellite transmissions are prone to both unintentional and intentional RF interference. Such interference has significant impact on the reliability of packet transmissions. In this paper, we make preliminary steps at exploiting the sensing capabilities of cognitive radios for reliable satellite communications. We propose the use of dynamically adjusted frequency hopping (FH) sequences for satellite [...]

Exploiting cognitive radios for reliable satellite communications 2016-02-10T09:52:32+00:00

A pre-emption framework for UMTS compatible satellite system supporting multimedia traffic

2016-02-10T09:52:40+00:00

SUMMARY The pre-emption procedure is an important part of the radio resource management when dealing with the emergency traffic. It allows resources to be allocated to higher priority connections by pre-empting lower priority connections. The provision of the pre-emption mechanism becomes much more important in the case of satellite systems such as the Inmarsat Broadband [...]

A pre-emption framework for UMTS compatible satellite system supporting multimedia traffic 2016-02-10T09:52:40+00:00

An improved authentication scheme for mobile satellite communication systems

2016-02-10T09:52:47+00:00

SUMMARY Recently, Lee et al. proposed a simple and efficient authentication scheme for mobile satellite communication systems. However, we find that their scheme is vulnerable to the smart card loss attack, the denial of service attack and the replay attack. To overcome the weaknesses of Lee et al.'s scheme, we proposed an authentication scheme for [...]

An improved authentication scheme for mobile satellite communication systems 2016-02-10T09:52:47+00:00

Experimental detection of mobile satellite transmissions with cyclostationary features

2016-02-10T09:52:55+00:00

ABSTRACTOne of the important functions of cognitive radio (CR) technology is spectrum sensing. The implementation of an efficient spectrum sensing function can be quite challenging because of various factors such as multi-path fading, low signal-to-noise ratio of the radio communication services to be detected and the requirement to detect and analyze the signal in a [...]

Experimental detection of mobile satellite transmissions with cyclostationary features 2016-02-10T09:52:55+00:00

The combined automatic repeat request and rate control mechanism in S-band mobile interactive multimedia asynchronous return link—design background, parameter dimensioning and first experimental results

2016-02-10T09:53:03+00:00

SUMMARY In the S-band mobile interactive multimedia specification, an asynchronous access using Enhanced Spread Spectrum Aloha random access has been defined for occasional messaging applications. This access scheme is complemented by a combined automatic repeat request and terminal rate control mechanism that is described in this paper. Furthermore, a queuing theory-based model is developed to [...]

The combined automatic repeat request and rate control mechanism in S-band mobile interactive multimedia asynchronous return link—design background, parameter dimensioning and first experimental results 2016-02-10T09:53:03+00:00

Enhanced spread Aloha physical layer design and performance

2016-02-10T09:53:13+00:00

SUMMARY This paper describes the key design and performance aspects of the Enhanced Spread Spectrum Aloha (E-SSA) physical layer, which represents an essential component of the S-band Mobile Interactive Multimedia European Telecommunication Institute standard. Thanks to advanced signal processing at the gateway side, the E-SSA random access protocol allows to achieve unprecedented spectral efficiency in [...]

Enhanced spread Aloha physical layer design and performance 2016-02-10T09:53:13+00:00

Transmission control protocol performance enhancement for mobile broadband interactive satellite communication system: a cross-layer approach

2016-02-10T09:53:21+00:00

SUMMARYMobile broadband interactive satellite communication system is of great interest in both academic and industrial communities. However, the conventional strict-layered protocol stack architecture and the standard TCP version perform poorly over satellite link. In this paper, we propose a comprehensive cross-layer Transmission Control Protocol (TCP) optimization architecture while considering the main factors that affect the [...]

Transmission control protocol performance enhancement for mobile broadband interactive satellite communication system: a cross-layer approach 2016-02-10T09:53:21+00:00