Commit e3ec0038 authored by U-RAJESH-SIS\rajesh's avatar U-RAJESH-SIS\rajesh

added notes

parent 3f448424
......@@ -17,7 +17,7 @@
\newcommand{\vt}[1]{\todo[backgroundcolor=green,inline]{\textbf{Vu:} #1}}
\newcommand{\am}[1]{\todo[backgroundcolor=red,inline]{\textbf{Archan:} #1}}
\newcommand{\jx}[1]{\todo[backgroundcolor=cyan,inline]{\textbf{Jie:} #1}}
\newcommand{\jx}[1]{\todo[backgroundcolor=yellow,inline]{\textbf{Jie:} #1}}
\newcommand{\raj}[1]{\todo[backgroundcolor=cyan,inline]{\textbf{Rajesh:} #1}}
\newcommand{\name}{{\em Anon\ }}
......
\section{Introduction}
\label{sec:intro}
Embedded sensors, deployed on small form-factor devices, have transformed our ability to pervasively observe the state of the physical world, including the monitoring of human activities, ambient context and machinery state. As obvious examples, (a) inertial or physiological sensors in wearable devices (such as smartwatches and smart-necklaces) have been used to monitor an individual's eating behavior~\cite{XXX}, smoking~\cite{XXX} or stress levels~\cite{XXX}; (b) vibration, audio or light sensors have been used on innovative IoT platforms to detect operating conditions and anomalies in factories, city neighborhoods and critical infrastructure.
Embedded sensors, deployed on small form-factor devices, have transformed
our ability to pervasively observe the state of the physical world,
including the monitoring of human activities, ambient context and machinery
state. As obvious examples, (a) inertial or physiological sensors in
wearable devices (such as smartwatches and smart-necklaces) have been used
to monitor an individual's eating behavior~\cite{XXX}, smoking~\cite{XXX} or
stress levels~\cite{XXX}; (b) vibration, audio or light sensors have been
used on innovative IoT platforms to detect operating conditions and
anomalies in factories, city neighborhoods and critical infrastructure.
\emph{Energy} remains perhaps the greatest challenge in the pervasive deployment of such sensing nodes: sensors such as accelerometers or gyroscopes simply consume too much energy to be operated continuously, without needing periodic recharge. Battery-powered sensing devices have two distinct disadvantages: (i) frequent recharging may simply be cumbersome or impractical--e.g., wearable-based health monitoring may be much more palatable if an embedded device may be worn for months without needing to be taken off and recharged; (ii) perhaps not as widely appreciated, high-density storage batteries can \emph{leak}, causing corrosion and other serious hazards, especially when the sensors are deployed in volume and out of sight (e.g., embedded inside factory equipment in industrial IoT settings).
......
......@@ -6,6 +6,9 @@ components of the system work.
\subsection{Experiment Setup \& Calibration}
\raj{still figuring out what to do here. we need to describe the base setup
and then extend it for the user study}
We setup our experiment in a meeting room, as shown in
Figure~\ref{fig:exprsetup}, to simulate an office environment.
The antenna sets are placed at the 2 corners of the table (Figure
......
......@@ -10,6 +10,11 @@ In this section, we present the overall functional architecture of \names, detai
\label{fig:overview}
\end{figure*}
\raj{maybe some more info on the super cap. what is it? why use it? I found out by
googling.. are supercaps as reliable as normal caps? do they tend to leak
more? how long will it store charge? for an expert reviewer, no issues.
for someone less expert, these questions might come out}
Figure~\ref{fig:XXX} shows the overall flow of \names. In this system, the wearable or embedded device (the `client') periodically transmits an omni-directional `ping' message (Step 1) . A WiFi AP computes the AoA (angle of arrival) of such a `ping' message and thereby establishes the client device's direction (angular orientation) relative to the AP (Step 2). The WiFi AP then transmits \emph{electronic beamformed} energy packets, effectively delivering a more concentrated dose of RF energy in the direction of the client device (Step 3). The client device then utilizes an RF energy-harvesting circuit (\am{Vu: say a bit more here}) to convert this passively-harvested RF energy into an electrical current, and store the resulting energy in a super-capacitor (Step 4). This supercapacitor thus acts as a nano-battery, providing the power needed to activate the sensing and communication modules of the client device, which then collects and transmits the sensor data (an accelerometer stream in our current implementation) to the backend infrastructure (Step 5).
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment