CC IoT added by Hui

Cloud Computing/lecturenotes.tex

@@ -7,6 +7,7 @@
 \graphicspath{{bilder/}}
 
 \usepackage{eurosym}
+\usepackage{mathtools}
 
 % Counter für das Blatt und die Aufgabennummer.
 \setcounter{sheetnr}{0} % Nummer des Übungsblattes
@@ -37,6 +38,7 @@
 	\input{lectures/faas.tex}
 	\input{lectures/monitoring.tex}
 	\input{lectures/autoscaling.tex}
+	\input{lectures/iot.tex}
 
 
 	% TODOS: REST API, container, orchestration, virtualization, docker VS. VM virtualization, hypervisor, service models, HPC & Cloud computing, VM migration, AWS availability, QoS, Kubernetes -- pods, minions, open source clouds, dockerfile, image file creation, Xeon Phi novel aspects, machine image, instance type, deployment models in microservice, lifecycle of VM, cost model serverless platform, infinite scaling, autoscaling approaches, step-scaling, normal read VS. strong consistent read, docker tag command

Cloud Computing/lectures/iot.tex

@@ -0,0 +1,66 @@
+\section{Internet of Things -- IoT}
+\begin{itemize}
+	\item Definition: a system of interrelated devices with unique identifiers, which can transfer data over network without human-human/human-computer interaction.
+	\item devices: mobile, alexa, sensors, vehicles, actuators, industrial machines, sweeping robots blabla.
+	\item applications: smart home/parking/health/city/agriculture blabla.
+
+
+\end{itemize}
+
+\subsection{IoT Architectures}
+
+\begin{itemize}
+	\item \textbf{cloud} architecture: devices $\xrightarrow[]{\text{IoT network}}$ Gateway $\xrightarrow[]{\text{WAN}}$ IoT platform on cloud data center
+
+
+	\item \textbf{edge} architecture: devices $\rightarrow$ \textbf{edge computers} $\xrightarrow[]{\text{WAN}}$ IoT platform on cloud data center
+	\begin{itemize}
+
+		\item \textbf{Preprocessing} computation nearer to devices (cloud too far \& slow). eg: aggregation, filtering on threshold, analysis. 
+
+		$\rightarrow$ smaller latency, saves bandwidth
+		\item use-case: compute devices on car/service robots(real-time)
+	\end{itemize}
+
+	\item \textbf{fog} architecture: devices $\xrightarrow[]{\text{IoT network}}$ Gateway $\rightarrow$ \textbf{islands of coupled edge devices} $\xrightarrow[]{\text{WAN}}$ IoT platform on cloud data center
+	\begin{itemize}
+		\item extension of edge architecture: an extra layer with coupled edge systems.
+		\item \textbf{distributed loaction awared shared} infrastructure
+		\item characteristics: contextual location awareness, low latency, heterogeneity(edge/accelerator/server for different processing purposes), real-time interactions, interoperatbility of different providers, scalability
+	\end{itemize}
+\end{itemize}
+
+\subsection{IoT Network}
+\begin{itemize}
+	\item wireless, connects devices to a gateway
+	\item \textbf{Low Power Wide Area Network(LPWAN)}: long distance, low power consuming for battery-charged devices
+
+
+	\item \textbf{Long Range Wide Area Network(LoRaWAN)}: 
+	\begin{itemize}
+		\item low frequency wave --> \textbf{long distance} >10km, for transferring \textbf{small messages}
+		\item \textbf{range overlapping}: device can communicate with server A \& B $\rightarrow$ \textbf{message duplication} at infrastructure $\rightarrow$ \textbf{De-duplication} necessary
+		\item based on \textbf{Chirp Spread Spectrum} modulation: spreading factor $\uparrow$, transmitting speed of a symbol $\downarrow$, amount of data transmitted$\downarrow$, payload size $\downarrow$
+		\item Use-case: The Things Network -- a global open LoRaWAN network
+	\end{itemize}
+
+\end{itemize}
+
+\subsubsection{The Things Network}
+\begin{itemize}
+	\item one network for the whole world.
+	\item long range gateways, for low power devices.
+	\item intermediate between low power devices and IoT infrastructures, servers, apps, etc.
+	\item Architecture \& Data Flow: a distributed system
+	\begin{itemize}
+		\item Gateway: distributed over the world, \textbf{devices} connect to \textbf{gateway}. 
+		\item Router: each \textbf{gateway} is connected to a \textbf{router}. Messages are forward to router or back.
+		\item Broker: \textbf{router} communicates to \textbf{broker}. Broker brings application and devices together, it forwards the message to the corresponding application.
+		\item network server: maintains the state of network, mapping between short address of device and network session key, identification of device
+		\item discovery: component discovery of routers and handlers.
+	\end{itemize}
+	\begin{figure}[H]
+		\centering
+		\includegraphics[width=0.8\textwidth]{ttn.png}
+	\end{figure}
+\end{itemize}