IEEE Communications Magazine — Communications Standards Supplement • December 2015
ABSTRACT
We propose the Safe Community Awareness
and Alerting Network (SCALE), a cyber-physical
system (CPS) leveraging the pervasive Internet
of Things (IoT) to extend a smarter, safer home
to all residents at a low incremental cost. SCALE
uses novel networking technolo-
gies, commodity sensor devices,
cloud services, and middleware
abstractions to sense, analyze,
and act on sensed events in a
distributed manner. It monitors environmental
factors (i.e. smoke, explosive gas) and automat-
ically alerts residents via phone upon discovery
of a possible emergency, enabling them to con-
frm the event and contact emergency dispatch-
ers with minimal effort. This article describes the
inception, design, development, and deployment
of a prototype system to achieve these goals. We
discuss lessons learned and future directions for
general CPS/IoT platforms.
INTRODUCTION
With the increasing pervasiveness of computers
in our daily lives, the Internet of Things (IoT)
concept is transitioning from a future prediction
to real-world deployments. With this manifes-
tation comes a myriad of possible applications,
from manipulating devices in our homes to large-
scale automation of industries and public utili-
ties. A common human-facing aspect of each of
these applications is that they aim to improve
our quality of life through inexpensive, common-
ly available technology. While home security
systems have existed for decades, they are rath-
er expensive services, and only in recent years
have we seen components become cheap and
available enough that hobbyists experiment with
do-it-yourself systems. So it seems natural that
an open system, made possible with these recent
advances, should be created to improve the lives
of under served populations that previously
could not afford such advanced home security
and safety monitoring systems. This motivation
led our team, assembled in response to the
SmartAmerica Challenge,
1
to envision, design,
build, and demonstrate the Safe Community
Awareness and Alerting Network (SCALE).
SCALE aims to improve the safety of resi-
dents through the use of modern connected
devices and computer systems, particularly low-
er-income and elderly residents who often do
not have access to advanced technologies such as
home security systems, smartphones, and com-
puters with Internet connections. To accomplish
this goal, we designed an event-driven distributed
system to sense safety-related data from devic-
es in homes or on individuals, analyze it locally
or within the cloud to detect possible emergen-
cy events, and automatically contact individuals
(e.g. homeowners, caretakers, even emergency
dispatchers) to notify them and confrm if there
is indeed an emergency. We implemented a pro-
totype of this system and deployed it in Mont-
gomery County, Maryland, USA to enable rapid
integration of components and testbeds from dif-
ferent partners.
The immediate goals of the SCALE project are:
• Demonstrate our ability to extend a con-
nected safe home to everyone at a low
incremental cost.
• Jump-start a live testbed for identifying and
researching IoT challenges (e.g. middle-
ware, networking, etc.).
• Identify suitable sensors,
data schemas, and algorithms
for detecting possible emer-
gency events.
• Implement and test work-
fows for cloud-based analytics and alerting.
• Demonstrate an open data platform for
connecting disparate systems with minimal
coordination.
SYSTEM ARCHITECTURE
SCALE devices upload sensed events, and the
analytics service looks for possible emergencies,
it sends residents emergency alerts to confrm or
reject, and interested individuals (i.e. emergency
dispatchers) visualize events through a dashboard.
This section discusses the high-level requirements,
logical components, architectural design decisions,
and implementation details of the system proto-
type. It first discusses a cloud data exchange and
then the components of the system that perform
sensing, analysis, and actuation.
CLOUD DATA EXCHANGE FOR IOT
To facilitate machine-to-machine (m2m) com-
munication for exchanging IoT data in SCALE
(sensed events, analytics, alerts, etc.), we pro-
pose the Data in Motion Exchange (DIME) sys-
tem, shown in Fig. 1. We envisioned DIME as an
open communications hub for IoT that simplifes
the development and deployment processes.
DIME allows any device or service to publish
or subscribe to any other data feed, regardless
of the protocols used at the device level. This
simple loose coupling enables developers to
incorporate new services and devices without the
need to modify existing ones. This simplifes sys-
tem evolution, and it also creates a level playing
feld for innovation. Any party can introduce new
SCALE: S AFE C OMMUNITY A WARENESS
AND A LERTING L EVERAGING THE
I NTERNET OF T HINGS
The authors propose the Safe Community Awareness and Alerting Network (SCALE), a
cyber-physical system (CPS) leveraging the pervasive Internet of Things (IoT) to extend a
smarter, safer home to all residents at a low incremental cost. SCALE uses novel networking
technologies, commodity sensor devices, cloud services, and middleware abstractions to sense,
analyze, and act on sensed events in a distributed manner.
Kyle Benson, Charles Fracchia, Guoxi Wang, Qiuxi Zhu, Serene Almomen, John Cohn, Luke D’Arcy,
Daniel Hofman, Mathew Makai, Julien Stamatakis, and Nalini Venkatasubramanian
COMMUNICATIONS
TANDARD
S S
27 0163-6804/15/$25.00 © 2015 IEEE
Kyle Benson, Guoxi
Wang, Qiuxi Zhu, and
Nalini Venkatasubrama-
nian are with University of
California.
Charles Fracchia is with
BioBright.
Serene Almomen and
Julien Stamatakis are with
Senseware, Inc.
John Cohn is with IBM.
Luke D’Arcy is with
Sigfox.
Daniel Hoffman is with
Montgomery County.
Matthew Makai is with
Twilio.
1
http://smartamerica.
org/