ULE Robust Header Compression For Ip-Based Communication Over Digital Video Broadcasting-Satellite (DVB-S) [TK5104. T261 2008 f rb].

Untuk selama 35 tahun, Internet telah berkembang dan bertumbuh dengan pesat. Disebabkan pembangunan yang mendadak, permintaan capaian Internet menjadi kian popular di mana-mana saja melalui pelbagai jenis media, Over a span of thirty five years, the Internet has developed and grown rapidly. Due to its rapid growth, the demand for Internet access today is everywhere and over every possible medium such as satellite communications

Performance Evaluation Of Unidirectional Lightweight Encapsulation Using ns-2 And DVB-S Testbed.

Unidirectional Lightweight Encapsulation (ULE) is a recently published standard to overcome the efficiency problems of Multi-Protocol Encapsulation for satellite data transmission. This paper presents a comparative study of Unidirectional Lightweight Encapsulation performance using ns-2 [ll simulation and a DVB-S testbed. Performance metrics such link utilization packet loss and latency were taken. It was found that the results of both approaches were comparabl

Digital Connectivity Bridging Digital ASEAN

The world is changing rapidly with the adoption of sophisticated digital technology. The foremost tool for digital technology operation is digital connectivity infrastructure. To unleash the potential of the digital economy in ASEAN countries, the foundation is upgrading its digital connection, which is a key part of making digitalization feasible. This study identified five factors that contributed to the digital connectivity of ten ASEAN countries and used them to calculate the overall score of each country to show its performance in terms of digital connectivity. The competitive analysis results of the five digital connectivity enablers in each country show their respective strengths and shortcomings. Myanmar made the greatest progress in overall digital connectivity, due to its engaging in national regulatory reforms and focusing connectivity developments after realizing the need to improve their ICT infrastructure. There is still much room for improvement in the network performance of ASEAN countries; among all ten countries, only Singapore has reached a very satisfactory level. Striving to narrow the digital connectivity development gap would be an important agenda item for all ASEAN countries

Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function

Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes

A Comparison of IP Datagrams Transmission using MPE and ULE over Mpeg-2/DVB Networks

Digital Video Broadcasting (DVB) defines the carriage of multimedia and internet information to client by means of MEPG-2 Transport Stream. The DVB standards also allow the same system to transmit Internet Protocol (IP) data. This data broadcasting technology enables the broadcast of large amount of data to the personal computer over satellite or other broadcasting network. This allows the MPEG-2 TS bearer become a hop in IP network. The intention of this paper is to compare the existing Multiprotoco

Performance evaluation of RObust Header Compression (ROHC) over undirectional links using DVB-S Testbed

Unidirectional Lightweight Encapsulation (ULE) was introduced to carry IP data over Unidirectional Link (UDL) using Digital Video Broadcasting via Satellite (DVB-S) system to overcome efficiency problems in satellite data communication. This paper introduces a method to further improve the efficiency of IP packets transmission over satellite communication system using RObust Header Compression (ROHC). ROHC is a framework to compress headers of IP packets. This paper presents a study of performance characteristics of ROHC over DVB-S via an actual satellite link. The analysis of results showed that header compression yields significant improvement in terms of data throughput when the payload sizes of IP packets are less than 512 bytes, typical of VOIP and other realtime traffic. Unidirectional Lightweight Encapsulation (ULE) は、衛星通信回線の片方向通信路（Unidirectional Link, UDL）上でDigital Video Broadcasting via Satellite (DVB-S) を用いて効率的なIP データ通信を行うための仕組みである。本稿では、RObust Header Compression (ROHC) を用いて、より効率的に衛星通信回線上でIP データ通信を行う手法を提案した。ROHC はIP ヘッダの圧縮手法である。実験により衛星通信回線上でDVB-S とROHC を利用した際の通信効率を測定し、解析した。その結果、VOIP 等のリアルタイム通信に多く使われる、512 バイト未満のIP パケットに適用することで、通信効率が大幅に改善することが判明した。特集 アジアにおけるネットワークと遠隔教育 招待論

Secrets in the sky: on privacy and infrastructure security in DVB-S satellite broadband

Demands for ubiquitous global connectivity have sparked a satellite broadband renaissance. Secure satellite broadband is vital to ensuring that this growth does not beget unanticipated harm. Motivated by this need, this paper presents an experimental security analysis of satellite broadband signals using the Digital Video Broadcasting for Satellite (DVB-S) protocol. This analysis comprises 14 geostationary platforms encompassing over 100 million square kilometers of combined coverage area. Using less than €300 of widely available equipment, we demonstrate the ability to identify individual satellite customers, often down to full name and address, and their web browsing activities. Moreover, we find that these vulnerabilities may enable damaging attacks against critical infrastructure, including power plants and SCADA systems. The paper concludes with a discussion of possible confidentiality protections in satellite broadband environments and notes a need for further cryptographic research on link-layer encryption for DVB-S broadband

Secrets in the sky: on privacy and infrastructure security in DVB-S satellite broadband

Demands for ubiquitous global connectivity have sparked a satellite broadband renaissance. Secure satellite broadband is vital to ensuring that this growth does not beget unanticipated harm. Motivated by this need, this paper presents an experimental security analysis of satellite broadband signals using the Digital Video Broadcasting for Satellite (DVB-S) protocol. This analysis comprises 14 geostationary platforms encompassing over 100 million square kilometers of combined coverage area. Using less than €300 of widely available equipment, we demonstrate the ability to identify individual satellite customers, often down to full name and address, and their web browsing activities. Moreover, we find that these vulnerabilities may enable damaging attacks against critical infrastructure, including power plants and SCADA systems. The paper concludes with a discussion of possible confidentiality protections in satellite broadband environments and notes a need for further cryptographic research on link-layer encryption for DVB-S broadband

The effect of genotype and in utero environment on interindividual variation in neonate DNA methylomes

Integrating the genotype with epigenetic marks holds the promise of better understanding the biology that underlies the complex interactions of inherited and environmental components that define the developmental origins of a range of disorders. The quality of the in utero environment significantly influences health over the lifecourse. Epigenetics, and in particular DNA methylation marks, have been postulated as a mechanism for the enduring effects of the prenatal environment. Accordingly, neonate methylomes contain molecular memory of the individual in utero experience. However, interindividual variation in methylation can also be a consequence of DNA sequence polymorphisms that result in methylation quantitative trait loci (methQTLs) and, potentially, the interaction between fixed genetic variation and environmental influences. We surveyed the genotypes and DNA methylomes of 237 neonates and found 1423 punctuate regions of the methylome that were highly variable across individuals, termed variably methylated regions (VMRs), against a backdrop of homogeneity. MethQTLs were readily detected in neonatal methylomes, and genotype alone best explained ?25% of the VMRs. We found that the best explanation for 75% of VMRs was the interaction of genotype with different in utero environments, including maternal smoking, maternal depression, maternal BMI, infant birth weight, gestational age, and birth order. Our study sheds new light on the complex relationship between biological inheritance as represented by genotype and individual prenatal experience and suggests the importance of considering both fixed genetic variation and environmental factors in interpreting epigenetic variation