The document describes the E-Flow system, a communication system that provides user notification in dynamic evacuation scenarios. E-Flow uses MQTT and XMPP protocols to connect sensors, users, and emergency responders to improve information awareness during evacuations. It was deployed at a university and two hospitals to test providing acceptable user awareness levels through a mobile app and web interface. The system analyzes response times to determine users receive information in under one second. Future work includes integrating decision support, stronger experimentation, and improving wireless sensor network integration.

1. E-Flow: A communication system for user
notification in dynamic evacuation scenarios
Augusto Morales
Technical University of Madrid
UCAmI 2013
Picture by David Gordillo
Costa Rica · December 2-6

2. The Evacuation Problem
• The evacuation analysis is a long-studied
problem.
• There are Route modeling systems, decision
support systems, middlewares, WSN and so on.
• There are several gaps of current evacuation
plans regarding the way users perceive the
information and are aware of the situation
2

3. Building and evacuation plan including
the user perspective
• Nowadays, there many solutions that
indeed permit WSN environments to
provide information in evacuation
situations.
• Nevertheless, there are other
challenges , more related to the
human factor, such as:
– reducing the reaction time of
personnel,
– reducing the interpretation time,
– providing easy interaction mechanisms
and
– Providing dynamic signaling.
3

4. How to improve the chances
of survival from the user
perpective?

5. To offer better information awareness!

6. Users
Safety staff
Emergency Response
Teams
Communication System for Dynamic
evacuation scenarios
Communication
Infraestructure
H2M Communication
Capabilities
M2M
Sensors/Actuators/
Signalling

7. Our solution is the Eflow
system

8. The BIG Picture of the E-Flow system
Proxy
MQTT
MQTT-to-Web Brokers
Faculty and
Students
XMPP
Servers
subscribe()
publish()
Local Network
Infraestructure
subscribe()
publish()
Wi-fi
Remote Networks
Mobile
Safety Staff
WSN
Wi-fi
Mobile
Broker
Pub/Sub
Client
Emergency
Response Teams
MQTT
Client
Concentrators 802.15
Sensors

9. User Awareness
Messaging Capabilities

10. E-Flow Implementation

11. Integration of Sensor/Actuators
Design from scratch
- low-power OMAPL127 (DSP+ARM) of TI
- 802.15.4
- PSOC3 of Cypress Semiconductor
- USB battery re-chargable
- Connected with Linux (Montavista)
- Sensors: presence, humidity,
Temperature, luminance
Actuator
Evacuation
signal
Concentrator
MQTT Client
Temperature
Usb
Sensors
Node 4
Humidity
Node 2
Node 1
(Central Node)
Evacuation
signal
Actuator
Temperature
Node 3
Node 5
Sensors
Humidity
Wireless Sensor Network (WSN)

12. Web-based application
Mobile Application (Android)
- Nodejs. Websockets-MQTT
- Openfire. XMPP
- Mosquitto MQTT broker
- Android (asmack, Alljoyn)

13. E-Flow Deployment

14. First Deployment at the Telecommunication School (UPM)

15. Second Deployment at Hospital de San José (Carabanchel,
Madrid)

16. Second Deployment at Hospital de San Pastor (Carabanchel,
Madrid)

17. results

18. Does the E-flow system provides acceptable
user awareness levels?
End-to-End
MQTT-to-Web using Websockets
Pub/Sub Network
MQTT only
Mean
Median
SD
Mean
Median
SD
a) Fixed
devices
30,977
29,770
1,056
4,740
4,515
0,904
b)
Mobile
devices
c) Proxy
Delay
246,983
250,989
11,893
65,904
66,938
4,111
4.402
4.520
0.830
-
-
-
We have checked the normality of the three samples with the Shapiro-Wilk normality test [23]
and conclude that the three samples came from a Normal distribution (p-value <= 0.05).
User experience and awareness are still acceptable for mobile cases. This
affirmation is based on the work of Jacob et al., which states that delays
less than 1.0 seconds need no special feedback.

19. summary

20. Proxy
MQTT
MQTT-to-Web Brokers
Faculty and
Students
XMPP
Servers
subscribe()
publish()
Local Network
Infraestructure
subscribe()
publish()
Wi-fi
Remote Networks
Mobile
Safety Staff
MQTT
Client
WSN
Wi-fi
Mobile
Broker
Concentrators 802.15
Sensors
Pub/Sub
Client
Emergency
Response Teams
E-flow system
provides user awareness

21. future work

22. Integrate decision
support system
stronger
experimentation
Better WSN
Integration

23. E-Flow: A communication system for user
notification in dynamic evacuation scenarios
Augusto Morales
Technical University of Madrid
UCAmI 2013
Picture by David Gordillo
Costa Rica · December 2-6