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diff --git a/usth/ICT2.10/midterm/main.tex b/usth/ICT2.10/midterm/main.tex new file mode 100644 index 0000000..0a33ca1 --- /dev/null +++ b/usth/ICT2.10/midterm/main.tex @@ -0,0 +1,439 @@ +\documentclass[pdf]{beamer} +\usepackage[english,vietnamese]{babel} +\usepackage{amsmath} +\usepackage{booktabs} +\usepackage{graphicx} +\usepackage{hyperref} +\usepackage{lmodern} +\usepackage{siunitx} + +\mode<presentation>{} +\usetheme[hideothersubsections]{Hannover} +\usecolortheme{crane} +\usefonttheme[onlymath]{serif} +\usebackgroundtemplate{ + \includegraphics[width=\paperwidth,height=\paperheight]{USTH.jpg}} +\renewcommand{\thefootnote}{\fnsymbol{footnote}} +\setcounter{tocdepth}{2} + +\title{Satellite Internet} +\author[Group 1]{Nguyễn Như Hiếu---BI9-103\\ + Ngô Ngọc Đức Huy---BI9-119\\ + Ngô Xuân Minh---BI9-167\\ + Nguyễn Gia Phong---BI9-184\\ + Nguyễn Hồng Quang---BI9-194\\ + Trần Minh Vương---BI9-239} +\institute{University of Science and Technology of Hà Nội} +\date{\selectlanguage{english}\today} + +\begin{document} +\frame{\titlepage} +\selectlanguage{english} +\begin{frame}{Contents} + \tableofcontents +\end{frame} + +\section{Introduction} +\frame{\tableofcontents[currentsection]} +\begin{frame}{Usage}\Large + \begin{block}{Popular Use} + \begin{itemize} + \item Airplane + \item Cruise Ship + \item Rural Area + \end{itemize} + \end{block} + \begin{block}{Similarity} + All three are either in or travel through area \\ + with little to no ground station. + \end{block} +\end{frame} + +\begin{frame}{Future Usage}\Large + Provide Internet for the whole world + + \begin{block}{Fact} + Over 3.7 Billion people are living without being \\ + connected to the internet. + \end{block} +\end{frame} + +\section{How It Works} +\frame{\tableofcontents[currentsection]} +\begin{frame}{Components} + \begin{itemize}\Large + \item Geostationary satellite (GEO) + \item Gateway + \item Antenna + \item Others: + \begin{itemize}\Large + \item Modem + \item Centralized NOC + \end{itemize} + \end{itemize} +\end{frame} + +\begin{frame}{Components Interaction} + \begin{figure} + \includegraphics[width=0.9\textwidth]{A-GPS.png} + \caption{GPS using A-GPS and GSM network} + \end{figure} +\end{frame} + + +\begin{frame}{One-way Satellite Network} +\Large + \begin{center} + \includegraphics[width=\textwidth]{one-way-to-earth.png} + \end{center} +\end{frame} + +\subsection{1-way from Earth} +\begin{frame}{Components}\large + \begin{itemize} + \item Upstream: Data travelling through telephone modem + \item Downstream: Download through satellite + \end{itemize} +\end{frame} + +\begin{frame}{Characteristics} + \begin{itemize} + \item Upload speed: Same as that of the dial-up internet + \item Download speed: Much faster than dial-up internet + \item Latency: Still high,much lower than two way satellite internet + \item You have to tie up the telephone lie when you use the Internet + \end{itemize} +\end{frame} + +\subsection{1-way to Earth} +\begin{frame}{One-way to Earth}\Large + \begin{block}{Components} + \begin{itemize} + \item 1 transmitting hub station (usually very large) + \item Multiple receive-only Earth stations + \end{itemize} + \end{block} +\end{frame} + +\begin{frame}{Characteristics}\Large + \begin{itemize} + \item Usage: IP multicast-based data,\\ + audio and video distribution + \item Interactivity: Little user interface,\\ + similar to TV or radio content + \end{itemize} +\end{frame} + +\subsection{2-way} +\begin{frame}{Two-way Satellite Network} + \begin{center} + \includegraphics[width=0.8\textwidth]{two-way.png} + \end{center} +\end{frame} + +\begin{frame}{Components}\LARGE + \begin{itemize} + \item VSAT: Send and receive data + \item Telecommunication port:\\ Relay data through Internet + \end{itemize} +\end{frame} + +\begin{frame}{Condition}\LARGE + Satellite dish must be precisely pointed\\ + to avoid interference. +\end{frame} + +\begin{frame}{Characteristics}\large + \begin{itemize} + \item Both TDMA and single channel per carrier + \item Mostly Ku-band, but also C-band and Ka-band + \item May utilize telephone modem to reduce latency + \item Home-user's bandwidth based on payment + \item Difficult on moving vehicles + \end{itemize} +\end{frame} + +\begin{frame}{Portable Satellite Internet} + \begin{block}{Portable} + \begin{itemize} + \item Use self-contained box pointed in general direction of Satellite + \item Expensive + \end{itemize} + \end{block} + \begin{block}{Satellite phone} + \begin{itemize} + \item Omnidirectional antenna so no alignment needed + \item Low bandwidth so slow to browse net,useful for sending email + \end{itemize} + \end{block} +\end{frame} + +\section{Limits and Challenges} +\frame{\tableofcontents[currentsection]} + +\subsection{Weather} +\begin{frame}{Heavy rain or Blizzard}\LARGE + \begin{itemize} + \item Fading + \item Accumulating raindrop or snow + \item Wind + \end{itemize} +\end{frame} + +\subsection{Latency} +\begin{frame}{Latency}\large + \begin{block}{Satellite altitude} + \begin{itemize} + \item LEO: $<$ \SI{2000}{\kilo\meter} + \item MEO: 2000--\SI{35786}{\kilo\meter} + \item GEO: $>$ \SI{35786}{\kilo\meter} + \end{itemize} + \end{block} + \begin{block}{Result} + GEO has 12 times higher latency than terrestrial base networks. + LEO and MEO have a bit lower delay. + \end{block} +\end{frame} + +\subsection{Others} +\begin{frame}{Other Limitations}\Large + \begin{block}{Economically} + Costly: \SI{2}{\mega b\per\second} costs around \$100 a month. + \end{block} + \begin{block}{Environmentally} + Space junk: Only 2000 out of 5000 launched satellites are still in function. + \end{block} +\end{frame} + +\section{Mitigations} +\frame{\tableofcontents[currentsection]} +\subsection{Techniques} +\begin{frame}{Fade Mitigation Techniques}\Large + Common functions: + \begin{itemize} + \item \emph{Monitor} link quality by continuous measurements + \item \emph{Predict} short-term behavior and duration\\ + of satellite channel's next state + \item \emph{Set} parameters based on previous estimation + \end{itemize} +\end{frame} + +\subsubsection{EIRP Control Techniques} +\begin{frame}{Effective Isotropic Radiated Power}\Large + \begin{itemize} + \item EIRP = tranmitted power $\times$ antenna gain + \item EIRP control = adjusting carrier power + or antenna gain to compensate for power losses + \end{itemize} +\end{frame} + +\begin{frame}{Power Control System} + \begin{enumerate}\large + \item Open loop: Based on recently received power. + \begin{itemize}\large + \item Non-reliable + \item Responsive + \end{itemize} + \item Closed loop: Based on channel power measurements. + \begin{itemize}\large + \item More comprehensive + \item Large propagation delay + \end{itemize} + \end{enumerate} +\end{frame} + +\begin{frame}{Uplink Power Control} + \begin{itemize} + \item Vary carrier power at the earth station + \item Restoration of side lobes might lead to\\ + adjacent \emph{channel} interference\\ + \includegraphics[width=0.54\textwidth]{lobes.png} + \item Increase of earth station transmit power may cause + adjacent \emph{satellite} interference\footnote{Satellites + are separated by 2--3 degrees on the geostationary orbit.\\} + \item Effective and preferred by many satellite operators + \end{itemize} +\end{frame} + +\begin{frame}{Downlink Power Control} + \begin{itemize}\Large + \item Vary carrier power on-board the satellite + \item Difficult to implement due to\\ satellite size and weight limitations + \item Subject to + \begin{enumerate}\large + \item Adjacent \emph{channel} interference + \item Inter\emph{modulation} interference + \item Inter\emph{system} interference (with terrestrial networks) + \end{enumerate} + \end{itemize} +\end{frame} + +\begin{frame}{Spot Beam Shaping}\Large + \begin{itemize} + \item Adjust antenna gain on-board the satellite\\ + for a certain geographical region + \item Shape satellite antenna for nearly constant\\ + ground receive power, even under rainfall + \item Does \textbf{not} need expensive calculations\\ + for attenuation estimation\footnote{SBS compensates + the entire coverage area instead of a single site.\\} + \item Technology and research are WIP + \end{itemize} +\end{frame} + +\subsubsection{Adaptive Transmission Techniques} +\begin{frame}{Adaptive Transmission Techniques} + \begin{itemize}\Large + \item Modify processing/transmission\\ manner of signals + \item Resource-shared techniques + \item Categories: + \begin{enumerate}\large + \item Hierarchical coding + \item Hierarchical modulation + \item Data rate reduction + \end{enumerate} + \end{itemize} +\end{frame} + +\begin{frame}{Hierarchical Coding}\large + \begin{itemize} + \item Add redundancy to the information signal + \item Trade-off between bandwidth and error probability + \item Different conditions require different coding schemes + \item Prioritize users with less efficient coding schemes, i.e.\\ + longer bursts (TDMA) or larger bandwidth (FDMA) + \end{itemize} +\end{frame} + +\begin{frame}{Hierarchical Modulation}\large + \begin{itemize} + \item Provide lower quality fallback in case of weak signals + \item Exchange bandwidth efficiency for power requirements + \item Suitable for localized satellite systems, e.g. VSAT + \item Users with lower-order modulation get more resources + \end{itemize} +\end{frame} + +\begin{frame}{Data Rate Reduction}\large + \begin{itemize} + \item Reduce information data rate for power gain + \item Distribute satellite resources equally to every user + \item Utilizable where significant information rate reduction\\ + is tolerable, e.g.\ video or data but voice transmission + \end{itemize} +\end{frame} + +\subsubsection{Diversity Protection Schemes} +\begin{frame}{Diversity Protection Schemes}\large + \begin{itemize} + \item Use multiple channels with different characteristics + \item Oriented against rain fades and highly efficient + \item Performance criteria + \begin{itemize} + \item Diversity gain: difference between site attenuation\\ + and joint attenuation, for the same probability level + \item Diversity improvement: ratio of site exceedence probability + to the joint one, for the same attenuation value + \end{itemize} + \end{itemize} +\end{frame} + +\begin{frame}{Diversity Techniques} + \begin{tabular}{l p{0.39\textwidth} l p{0.18\textwidth}} + \toprule + \textbf{Diversity} & \textbf{Setup} & \textbf{Efficiency} & \textbf{Cost}\\ + \midrule + Site & Connected earth stations & High & High\\ + Orbital & Earth station may choose\newline between satellites & Low & Low\\ + Frequency & Use lower frequency\newline on higher attenuation + & Adaptive & Terrestrial equipments\\ + Time & Repeat faded data & Selective\footnote{\ldots of fade duration} & N/A\\ + \bottomrule + \end{tabular} +\end{frame} + +\subsection{Comparison} +\begin{frame}{EIRP Control Techniques} + \begin{table} + \begin{tabular}{l l p{0.27\textwidth} p{0.2\textwidth}} + \toprule + \textbf{Tech} & \textbf{Availability} + & \textbf{Max gain} (dB) & \textbf{Cons} \\ + \midrule + ULPC & 0.01--10 \% & 5 (VSAT)\newline 15 (hubs)& power range \\ + DLPC & 0.01--10 \% & 3 (sat.~TWTA) & power range \\ + SBS & 0.01--1 \% & 5 (sat.~antenna) & immature research \\ + \bottomrule + \end{tabular} + \caption{Comparisons between EIRP control techniques} + \end{table} +\end{frame} + +\begin{frame}{Adaptive Transmission Techniques} + \begin{table} + \begin{tabular}{l l p{0.25\textwidth} p{0.23\textwidth}} + \toprule + \textbf{Tech} & \textbf{Availability} + & \textbf{Max gain} (dB) & \textbf{Cons} \\ + \midrule + HC/HM & 0.01--10 \% & 10--15\newline ($E_b/N_0$ range) + & fading in \newline many stations \\ + DDR & 0.01--10 \% & 3--9 & low rate\newline intolerant \\ + \bottomrule + \end{tabular} + \caption{Comparisons between adaptive transmission techniques} + \end{table} +\end{frame} + +\begin{frame}{Diversity Protection Schemes} + \begin{table} + \begin{tabular}{l l p{0.25\textwidth} p{0.24\textwidth}} + \toprule + \textbf{Tech} & \textbf{Availability} + & \textbf{Max gain} (dB) & \textbf{Cons} \\ + \midrule + SD & 0.001--0.1 \% & 10--30\newline (conv.~rain) & cost \\ + OD & 0.001--1 \% & 3--10 & satellite switch \\ + FD & 0.01--10 \% & 30 (Ka--Ku) & cost\\ + \bottomrule + \end{tabular} + \caption{Comparisons between diversity protection schemes} + \end{table} +\end{frame} + +\section{Conclusion} +\frame{\tableofcontents[currentsection]} +\begin{frame}{Conclusion}\LARGE + \begin{itemize} + \item Have many potentials + \item Challenging + \item Need more research + \end{itemize} +\end{frame} + +\begin{frame}{References} + \begin{thebibliography}{69} + \setbeamertemplate{bibliography item}[article] + \bibitem{KuKaV} Athanasios D.~Panagopoulos,\\ + Pantelis-Daniel M.~Arapoglou and Panayotis G.~Cottis.\\ + ``Satellite communications at Ku, Ka, and V bands: + Propagation impairments and mitigation techniques''.\\ + \emph{Communications Surveys \& Tutorials}, vol.~6, p.~2--14.\\ + IEEE, 2004. doi:10.1109/COMST.2004.5342290. + \setbeamertemplate{bibliography item}[online] + \bibitem{wiki} Satellite Internet access. \emph{Wikipedia}. + \end{thebibliography} +\end{frame} + +\begin{frame}{Copying}\Large + \begin{center} + \includegraphics[width=0.2\textwidth]{CC.png} + \includegraphics[width=0.2\textwidth]{BY.png} + \includegraphics[width=0.2\textwidth]{SA.png} + \end{center} + + This work is licensed under a + \href{https://creativecommons.org/licenses/by-sa/4.0/}{Creative Commons + Attribution-ShareAlike 4.0 International License}. +\end{frame} +\end{document} |