My Ph.D. dissertation defense! :) With the number of Global Positioning System (GPS)-enabled mobile phones rapidly increasing due to maturing positioning technologies, intelligent location-aware applications are poised to become the next innovation in mobile phones. However, innovations bring new challenges. As cellular data networks achieve broadband speeds, constrained device resources (e.g. battery life) replace bandwidth as a primary limiting factor for mobile applications. IP-based networking protocols, now widely available in Java Micro Edition devices, must be carefully integrated into existing architectures to meet application needs and maximize system efficiency. Evolving location-aware architectures require intelligent clients for low-latency real-time applications and efficient management of device resources, as well as server-side intelligence to analyze past user behavior. This paper expands previous work on location-aware architectures and presents Location-Aware Information Systems Client (LAISYC), a comprehensive location-aware framework supporting intelligent real-time mobile applications. Short version is in this IEEE Pervasive Computing publication: http://bit.ly/IEEE_Per_Com_LAISYC Full dissertation: http://bit.ly/BarbeauDissertation

1. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
A Location-Aware Architecture Supporting
Intelligent Real-time Mobile Applications
Sean J. Barbeau, M.S.
Research Associate - Center for Urban Transportation Research
Ph.D. Candidate - Department of Computer Science & Engineering
University of South Florida

2. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Agenda
 Introduction
 Known LBS Architectures
 Limitations of Current LBS
 Proposed LAISYC Architecture
 Evaluation
 Conclusions
 Permissions and Notices
2
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

3. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Opportunities for Mobile Applications
3
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

4. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Mobile Computing Opportunities
 Proliferation of cell phones & apps
 5.9B mobile subscriptions worldwide, approx. 87% of global
population (Sept. 11)[1]
 102.4% U.S. mobile subscriber rate (322.9M) (Jun. 11) [2]
 26.6% of U.S. Households are Wireless–Only (April 11) [3]
 29B apps downloaded in 2011, up from 9B in 2010 [4]
 Evolution of positioning technologies
 U.S. F.C.C. e-911 mandate for locating cell phones ~2001
 79.9% of cell phones shipped in Q4 2011 (318.3M) had
integrated GPS [5]
[1] International Telecommunications Union, “ITC Facts and Figures – The World in 2011” International Telecommunications Union, Sept 2011.
[2] CTIA. “Wireless Quick Facts,” http://www.ctia.org/advocacy/research/index.cfm/aid/ 10323
[3] National Center for Health Statistics. “Wireless Substitution: State-level Estimates from the National Health Interview Survey”, National Health Statistics Reports, Number 39, April 20, 2011.
[4] ABIresearch. “Android Overtakes Apple with 44% Worldwide Share of Mobile Apps Downloads,” October 24, 2011.
[5] Rebello, Jagdish. “Four Out of Five Cell Phones to Integrate GPS by End of 2011,” Integrate-GPS-by-End-of-2011.aspx
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
4

5. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Examples of currently known LBS apps and architectures
5
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

6. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Google Maps/Inrix/Foursquare/Facebook/Latitude
 Maps and Navigation
 Real-time traffic
 Allows users to “check-in”
to locations to earn
points/rewards/discounts
 Alerts you to friend check-
ins
 Limitations:
 Proprietary
 User-managed location
6
Sugar
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

7. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Known LBS Architectures
 Evolution of architectures has been from low to high
levels in the device and network stacks
7
Link Layer
(e.g., CDMA IS-95)
Network Layer
(e.g., IP)
Tranport Layer
(e.g., TCP, UDP)
Application Layer
(e.g., HTTP, FTP, VOIP)
Hardware
(e.g., Qualcomm chipset)
Operating System
(e.g., Linux)
Virtual
Machine
(e.g., Java ME)
3rd
party
Apps
Embedded
Apps
Device Cell Network
Introduction
Known LBS
Architectures
Challenges
Proposed LAISYC
Architecture
Evaluation Conclusions
Hardware
(e.g., Intel CPU/
Motherboard)
Operating System
(e.g., Linux)
Application
Server
Server

8. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Link Layer
(e.g., CDMA IS-95)
Network Layer
(e.g., IP)
TCP
Session
Initiation
Protocol
(SIP)
HTTP
RTP/RTSP
SOAP
(Using
XML)
Hardware
(e.g., Qualcomm chipset)
Operating System
(e.g., Linux)
Virtual
Machine
(e.g., Java ME)
3rd
party
Apps
Embedded
Apps
 Recent arch. are based on mobile apps
 Proposed protocols - Session Initiation Protocol (SIP), and
Simple Object Access Protocol (SOAP) with XML
8Device Cell Network + Internet
Introduction
Known LBS
Architectures
Challenges
Proposed LAISYC
Architecture
Evaluation Conclusions
Known LBS Architectures
Hardware
(e.g., Intel CPU/
Motherboard)
Operating System
(e.g., Linux)
Application
Server
Server
3rd
party Apps
Hardware
(e.g., Qualcomm chipset)
Operating System
(e.g., Linux)
Virtual
Machine
(e.g., Java ME)
3rd
party
Apps
Embedded
Apps

9. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Location-Aware Application
(Device-side)
Server
Legend
Location Data
Device Platform Software
Location API I/O API
Virtual Machine
Java ME / Android
9
Known LBS Architectures
1. Obtain GPS at fixed interval (e.g., every 4 s)
2. Send data to server via SOAP or SIP
1. Fixed-
interval
Location
updates
2. Send data to server
SOAP
/ SIP
Mobile Device

10. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Limitations of known architectures
10
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

11. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Known Arch. Limitations
1. Battery energy limitations are not addressed
11
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

12. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Known Arch. Limitations
 Frequent GPS sampling (4 s) and transmissions to
server cost significant battery energy
12
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
Location-Aware Application
(Device-side)
Server
Legend
Location Data
Device Platform Software
Location API I/O API
Virtual Machine
Java ME / Android
1. Fixed-
interval
Location
updates
2. Send data to server
SOAP
/ SIP
Mobile Device

13. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
14
8.04
0
2
4
6
8
10
12
14
16
4 sec. sampling interval
BatteryLife(hours)
Impact of GPS on Battery Life
Requirement
Sanyo Pro 200
13
Sprint CDMA
EV-DO Rev. A
network
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

14. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
14
7.02
0
2
4
6
8
10
12
14
16
4 sec. Tx interval
BatteryLife(hours)
Impact of Wireless Tx on Battery Life
Requirement
Motorola i580
14
Nextel iDEN
Network
JAX-RPC
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

15. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
14
4.21
0
2
4
6
8
10
12
14
16
4 sec. sampling interval
BatteryLife(hours)
Impact of GPS & WirelessTx
on Battery Life
Requirement
Sanyo Pro 200
15
Sprint CDMA
EV-DO Rev. A
Network
UDP
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

16. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Known Arch. Limitations
1. Battery energy limitations are not addressed
2. Cellular data transfer limitations are not
addressed
16
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

17. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Cellular Data Transfer Limitations
 Location tracking once per second
equals 86,400 records (~10.3MB) for
one user on one day
 Most cellular carriers only offer
limited data plans
 e.g., Verizon = $20 per month for 1GB
 ~10.3MB per day = 319.3MB per
month
 Almost 1/3 of user’s plan would be
location data
17
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

18. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Known Arch. Limitations
1. Battery energy limitations are not addressed
2. Cellular data transfer limitations are not addressed
3. Lack of integration with existing platforms on
commercially-available devices
18
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

19. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
 SOAP and SIP w/ location APIs aren’t available on
Java Micro Edition, Android, iPhone
19
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
Location-Aware Application
(Device-side)
Server
Legend
Location Data
Device Platform Software
Location API I/O API
Virtual Machine
Java ME / Android
Send data to server
SOAP
/ SIP
Mobile Device

20. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Known Arch. Limitations
1. Battery energy limitations are not addressed
2. Cellular data transfer limitations are not addressed
3. Lack of integration with existing platforms on
commercially-available devices
4. Lack of evaluation of efficacy of location-aware
architectures
20
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

21. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Lack of evaluation on real devices
 Devices, cellular plans are expensive
 On Java Micro Edition, Location API access has been
restricted to carrier industry partners
 Laptops, emulators, and simulations have been used as
proxies for real devices
 Do not model energy consumption
 Do not consider GPS error
 Make sets of assumptions that don’t apply to real devices
21
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

22. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Key Challenges
 How do we add device-based intelligence to reduce
energy expenditures while supporting real-time
apps?
 We must consider that:
 Acting on real-time data consumes limited device
resources
 Mobile hardware is proprietary and rapidly changing
22
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

23. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
How can we advance the state-of-the-art in LBS?
23
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

24. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Demand for a new LBS architecture
Should meet following needs:
 Need #1 - Intelligently manages limited
device/network resources (e.g., battery energy)
 Need #2 - Support real-time applications
 Need #3 - Support high-precision and high-accuracy
positioning systems
 Need #4 - Is fully implementable by third-party
mobile app developers
 This is the goal of this dissertation
24
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

25. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Location-Aware Information SYstems Client (LAISYC)
25
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

26. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
LAISYC Architecture
26
LAISYC -
Server-side
Web Application Server
LAISYC -
Device-side
Mobile App
Mobile Device
Web Application
Server-based softwareDevice-based software
Database Server
Persistent Datastore
App/Location DataApp/Location Data
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
 My dissertation focus = LAISYC device-side modules

27. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
LAISYC – Device components
27
Critical
Point
Algorithm
Location Data Signing
GPS Auto-Sleep
Adaptive
Location
Buffering
Location
Data
Encryption
SessionManagement
Legend
Real-time Phone-Generated
Location Data Flow
Control Signals
Application Data Flow
UDP
HTTP(S)
TCP
Location Data
Flow Control
Device Platform Software
LAISYC – Communications
Management
LAISYC – Positioning
Systems Management
Server
Location API Persistent Storage API I/O API
Virtual Machine
Java ME / Android
LAISYC Comm. APILAISYC Positioning API
Location-Aware Application
(Device-side)
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

28. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
LAISYC – Server components
28
UDP
HTTP(S)
TCP
Critical
Point
Algorithm
Application Server
Spatial
Database
SessionManagement
Spatial
Analysis
Adaptive
Location
Data
Buffering
(Control Only)
Relational
Database
Mobile
Phone(s)
Legend
Real-time Phone-Generated
Location Data Flow
Control Signals
Application Data Flow
Location Data
Flow Control
LAISYC – Communications
Management
LAISYC – Data Analysis
Existing Software Solutions
LAISYC Comm. API
LAISYC Data
Analysis API
Location-Aware Application
(Server-side)
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

29. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
LAISYC Device-side Modules and Needs
LAISYC
Device-side
Modules
Need #1:
Intelligently
manages limited
device/network
resources
Need #2:
Still supports
real-time
applications?
Need #3:
Supports high-
precision and high-
accuracy positioning
systems
Need #4:
Fully implementable
by 3rd party mobile
app developer
Session
Management
X X X*
GPS Auto-Sleep
X X X X*
Critical Point
Algorithm
X X X X
Adaptive
Location
Buffering
X X X*
Location Data
Encryption X X X
Location Data
Signing
X X X
29
*Interacts directly with the mobile device platform via Application Programming Interfaces (APIs)
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
Today’s
presentation

30. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
U.S. Patent # 8,036,679 – Optimizing performance of location-aware applications
using state machines.
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011. © 2011 IEEE
Proceedings of IEEE UBICOMM 2008 – The Second International Conference on
Mobile Ubiquitous Computing, Systems, Services, and
Technologies, Valencia, Spain, September 29 – October 4, 2008. © 2008 IEEE
The Journal of Navigation, volume 64, issue 03, pp. 381-399. July 2011. © 2011
The Royal Institute of Navigation.
30
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

31. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
GPS Auto-Sleep
31
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
GPS Auto-Sleep
Critical
Point
Algorithm
Location Data Signing
Adaptive
Location
Buffering
Location
Data
Encryption
SessionManagement
Legend
Real-time Phone-Generated
Location Data Flow
Control Signals
Application Data Flow
UDP
HTTP(S)
TCP
Location Data
Flow Control
Device Platform Software
LAISYC – Communications
Management
LAISYC – Positioning
Systems Management
Server
Location API Persistent Storage API I/O API
Virtual Machine
Java ME / Android
LAISYC Comm. APILAISYC Positioning API
Location-Aware Application
(Device-side)

32. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
GPS Tracking
 “High-definition” view of
travel
 Frequent sampling allows
us to determine:
 Path, distance traveled
 Origin-Destination pairs
 Avg. speeds
 Enables high-accuracy real-
time, historical LBS
 Challenges:
 Battery life
 Amount of data
32
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

33. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
GPS Tracking
 Infrequent tracking
solves energy, data
problems
 BUT, doesn’t give us the
data we want:
 Path, distance traveled
 Origin-Destination pairs
 Avg. speeds
33
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

34. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
 Purpose – to save battery energy & reduce data transfer
to server by dynamically adjusting the GPS sampling
interval based on user movement
 Change states based on speed/distance/time thresholds
GPS-Auto Sleep
ASLEEPAWAKE
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
State
[0]
State
[1]
State
[n – 1]
State
[n]
Move directly to state[0] when current_speed >
high_speed_threshold.
GPS Sampling
Interval = 4 sec.
GPS Sampling
Interval = 8 sec.
GPS Sampling
Interval = 128 sec.
GPS Sampling
Interval = 256 sec.
After leaving state[0], gradually move towards state[n] when ((current_speed <
low_speed value) AND (distance_between_fixes < moved_distance_threshold))
OR if a GPS fix can’t be acquired.
Gradually move towards state[0] when
(low_speed_threshold < current_speed <
high_speed_threshold) OR
(distance_between_fixes >
moved_distance_threshold).
34

35. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
State
[0]
State
[1]
State
[n – 1]
State
[n]
Move directly to state[0] when current_speed >
high_speed_threshold.
GPS Sampling
Interval = 4 sec.
GPS Sampling
Interval = 8 sec.
GPS Sampling
Interval = 128 sec.
GPS Sampling
Interval = 256 sec.
After leaving state[0], gradually move towards state[n] when ((current_speed <
low_speed value) AND (distance_between_fixes < moved_distance_threshold))
OR if a GPS fix can’t be acquired.
Gradually move towards state[0] when
(low_speed_threshold < current_speed <
high_speed_threshold) OR
(distance_between_fixes >
moved_distance_threshold).
ASLEEPAWAKE
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
35

36. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011,
doi:10.1109/MPRV.2010.48 © 2011 IEEE
The Journal of Navigation, volume 64, issue 03, pp. 381-399. July 2011. ©
2011 The Royal Institute of Navigation.
Proceedings of IEEE UBICOMM 2008 – The Second International
Conference on Mobile Ubiquitous Computing, Systems, Services, and
Technologies, Valencia, Spain, September 29 – October 4, 2008. © 2008
IEEE
36
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

37. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Critical Point Algorithm
37
Critical
Point
Algorithm
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
Location Data Signing
GPS Auto-Sleep
Adaptive
Location
Buffering
Location
Data
Encryption
SessionManagement
Legend
Real-time Phone-Generated
Location Data Flow
Control Signals
Application Data Flow
UDP
HTTP(S)
TCP
Location Data
Flow Control
Device Platform Software
LAISYC – Communications
Management
LAISYC – Positioning
Systems Management
Server
Location API Persistent Storage API I/O API
Virtual Machine
Java ME / Android
LAISYC Comm. APILAISYC Positioning API
Location-Aware Application
(Device-side)

38. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
38
Critical Point Algorithm
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
38
 Purpose – to reduce battery energy expenditures and amount
of data transferred by eliminating non-essential GPS data
 Pre-filters real-time GPS data on mobile device before it is
wirelessly transmitted

39. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Critical Point Algorithm
39
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
changeInDirection() = |Angle2 – Angle1|
NORTH
Last Critical Point
Current Point
Last Trigger Point
(Under Evaluation)
Angle1
Angle2
= Mobile Device Path
= Location Points

40. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
40
START
(Input = currentLocation)
TransportationMode=
WALKING
TransportationMode=
VEHICLE
First Point?
lastCriticalPoint=
currentLocation
lastCriticalPoint=lastTriggerPoint
YES
NO
YES
NO
YES
NO
(Since currentLocation is first point in
sequence, it is saved as both the
lastCriticalPoint and LastValidPoint)
(lastTriggerPoint is a CriticalPoint, and
is stored as lastCriticalPoint for future
executions of CP algorithm and
returned to application)
(No Critical Points were found)
NO
YES
Return currentLocation
lastTriggerPoint=
currentLocation
lastTriggerPoint=currentLocation
(Optional) Reset Conditional
Evaluation Variables
(for Real-time Applications)
Return lastCriticaPointReturn null
Speed >
max_walk_speed
(Optional)
Conditional Evaluations = TRUE?
(for Real-time Applications)
(changeInDirection() >
angle_threshold) AND
(currentSpeed >
min_speed_threshold)?
 changeInDirection()
 Uses angle threshold
 Changed per speed
 min_speed()
 If currentSpeed >
min_speed, device is moving
 Real-time Conditional
Evaluations (Optional)
 timerExpired()?
 distanceCounterExceeded?
 receivedServerProbe?
Critical Point
Algorithm

41. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept.
2011, doi:10.1109/MPRV.2010.48 © 2011 IEEE
IEEE Communications Magazine, Vol. 44, No. 11, pp. 156-
163, November 2006. © 2006 IEEE
IEEE Network Magazine, Vol.24 No.4, July 2010. © 2010 IEEE
41
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

42. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
42
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
Critical
Point
Algorithm
Location Data Signing
GPS Auto-Sleep
Adaptive
Location
Buffering
Location
Data
Encryption
Legend
Real-time Phone-Generated
Location Data Flow
Control Signals
Application Data Flow
UDP
HTTP(S)
TCP
Location Data
Flow Control
Device Platform Software
LAISYC – Communications
Management
LAISYC – Positioning
Systems Management
Server
Location API Persistent Storage API I/O API
Virtual Machine
Java ME / Android
LAISYC Comm. APILAISYC Positioning API
Location-Aware Application
(Device-side)
Session Management
SessionManagement

43. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Session Management
Purpose - to save battery energy and reduce data transfer
while supporting real-time location data communication
Transmits two types of data:
1. Location data (e.g., latitude, longitude, time):
 Real-time, streaming data exchange
 Timeliness, efficiency is more important than 100% reliability
 We choose User Datagram Protocol (UDP) instead of
Transmission Control Protocol (TCP) for energy and
timeliness benefits
2. Application data (e.g., server login)
 Request-response model
 Reliable, occasional data exchange
 We choose web services to transfer this data in LAISYC
43
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

44. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
2. App Data – SOAP vs. HTTP
 Two common ways to implement web services:
 SOAP
 XML-based messaging protocol
 Advanced functionality
 HTTP (e.g. REST-ful Web Service)
 Directly uses HTTP methods
 (e.g. POST)
 No additional tags required for data
 We chose HTTP-POST for energy
and data efficiency
44
Layered Networking Model
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
44
TCP
(Transport Layer)
HTTP
(Application Layer)
SOAP
(using XML tags)
UDP
(Transport Layer)

45. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept.
2011, doi:10.1109/MPRV.2010.48 © 2011 IEEE
45
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

46. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Adaptive Location Data Buffering
 Purpose - To increase the reliability of real-time
location data communication with the server in an
energy-efficient manner.
 UDP does not have any guaranteed quality of service
 While occasional loss of location data over UDP is
acceptable, large gaps in data are problematic:
 Sparse network coverage
 Active voice calls on CDMA devices
 Solution – occasionally query server via TCP, buffer
data if TCP fails
46
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

47. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Adaptive Location Data Buffering
47
Server
Mobile
Device Data is
buffered
because of
TCP failure
All Buffered
Data is sent
because
of TCP success
UDP Transmission
(successful)
TCP Transmission
(successful)
UDP Transmission
(Failed)
TCP Transmission
(Failed)
Key
t 0

48. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Quantification of architecture module benefits
48
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

49. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
U.S. Patent # 8,036,679 – Optimizing performance of location-aware
applications using state machines.
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011. © 2011
IEEE
Proceedings of IEEE UBICOMM 2008 – The Second International Conference on
Mobile Ubiquitous Computing, Systems, Services, and
Technologies, Valencia, Spain, September 29 – October 4, 2008. © 2008 IEEE
The Journal of Navigation, volume 64, issue 03, pp. 381-399. July 2011. © 2011
The Royal Institute of Navigation.
49
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

50. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
50
8.04
10.71
13.01
14.20
15.68
18.77
41.94
0
5
10
15
20
25
30
35
40
45
4 8 15 30 60 150 300
BatteryLife(hours)
Interval Between GPS Fixes (s)
Impact of Interval Between GPS Fixes on
Battery Life
Sanyo
Pro 200
Sprint CDMA
EV-DO Rev. A
network
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

51. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
GPS Auto-Sleep
 Uses several thresholds for states changes (based on observed
data):
 stopped_speed_threshold = 1 m/s
 95th percentile of speed error
 high_speed_threshold = 1.5 m/s
 98th percentile of speed error
 moved_distance_threshold = 100 m
 Based on max. observed horizontal error of 90.69 m
 high_horizontal_accuracy_threshold = 80 m
 Based on max. observed hor. acc. of 58 m
 first_fix_timeout = 20 sec.
 backoff_time_threshold = 120 sec.
 Running time -
 Memory requirement -
where = number of GPS data points processed
51
𝑓 𝑛 = 𝑂 𝑛
𝑛
𝑓 𝑛 = 𝑂(1)

52. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
52
0
50
100
150
200
250
300
1
23
45
67
89
111
133
155
177
199
221
243
265
287
309
331
353
375
397
419
441
463
485
507
529
551
573
595
617
639
661
683
705
727
749
771
793
815
837
859
881
903
925
947
969
991
1013
1035
IntervalBetweenGPSFixes(seconds)
GPS Auto-Sleep Transitions - “Awake” to “Asleep”
Sanyo Pro 200
Sprint CDMA
EV-DO Rev. A
network
“Asleep”
“Awake”
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
State errors
No GPS signal

53. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
53
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
0.51%
29.10%
11.60% 10.54%
15.67%
23.97%
7.37%
0.00%
5.00%
10.00%
15.00%
20.00%
25.00%
30.00%
35.00%
Min Max Mean 50th 68th 95th STD DEV
GPS Auto-Sleep -
State ErrorPercentage
 Approx. 88% mean accuracy in state tracking
 Avg. doubling of battery life (based on TRAC-IT tests)
n = 30

54. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept.
2011, doi:10.1109/MPRV.2010.48 © 2011 IEEE
The Journal of Navigation, volume 64, issue 03, pp. 381-399. July 2011. ©
2011 The Royal Institute of Navigation.
Proceedings of IEEE UBICOMM 2008 – The Second International
Conference on Mobile Ubiquitous Computing, Systems, Services, and
Technologies, Valencia, Spain, September 29 – October 4, 2008. © 2008
IEEE
54
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

55. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
55
Sanyo 7050
Sprint CDMA
1xRTT Network
UDP
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
Effect of Wireless Transmission Interval on Battery Life

56. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Critical Point Algorithm
 Uses several thresholds for filtering points, based on observed
data:
 min_speed_threshold = 0.1 m/s
 Based on walk speed 25th percentile of 0.2 m/s, 20th percent. of 0 m/s
 max_walk_speed = 2.6 m/s
 Used to determine angle_threshold
 Mean max. walk speed just over 2.5 m/s from literature
 angle_threshold = 4.5 degrees for walk trips, 3 degrees for car
trips
 Methodology shown in following slides
 Running time -
 Memory requirement -
where = number of GPS data points processed
56
𝑓 𝑛 = 𝑂 𝑛
𝑛
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
𝑓 𝑛 = 𝑂(1)

57. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 1
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
57

58. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 2
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
58

59. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 3
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
59

60. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 4
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
60

61. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 5
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
61

62. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 6
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
62

63. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 7
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
63

64. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 8
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
64

65. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 10
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
65

66. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 11
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
66

67. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 15
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
67

68. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
• Angle 18
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
68

69. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Accuracy Evaluation using Distance
69
Sampled GPS position
Critical Point path
Full GPS Path
Critical Point
a
b c d
e
f
g
x
y
Distancefull_GPS_path = a + b + c + d + e + f + g
Distancecritical_point_path = x + y
𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑒𝑟𝑟𝑜𝑟 𝑝𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 =
𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒𝑓𝑢𝑙𝑙 _𝐺𝑃𝑆_𝑝𝑎𝑡 𝑕 − 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒𝑐𝑟𝑖𝑡𝑖𝑐𝑎𝑙 _𝑝𝑜𝑖𝑛𝑡 _𝑝𝑎𝑡 𝑕
𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒𝑓𝑢𝑙𝑙 _𝐺𝑃𝑆_𝑝𝑎𝑡 𝑕
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

70. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
0.00%
2.00%
4.00%
6.00%
8.00%
10.00%
12.00%
14.00%
16.00%
18.00%
20.00%
0
10
20
30
40
50
60
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
DistanceErrorPercentage
NumberofCriticdalPoints
Angle Threshold (Degrees)
Number of Critical Points Total Number of Points Distance Error Percentage
# Critical Points vs. Distance Error Percentage
Walk
70
Chosen Walk
Angle Threshold
= 4.5 degrees
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

71. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
0.00%
2.00%
4.00%
6.00%
8.00%
10.00%
12.00%
14.00%
16.00%
18.00%
20.00%
0
50
100
150
200
250
300
350
400
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
DistanceErrorPercentage
NumberofCriticdalPoints
Angle Threshold (Degrees)
Number of Critical Points Total Number of Points Distance Error Percentage
# Critical Points vs. Distance Error Percentage
Car
71
Chosen Car
Angle Threshold
= 3 degrees
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

72. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
 Avg. GPS reduction of 77% per trip
 Avg. 18.8kB saved per trip
 Average distance error percentage under 10%
 On avg., as Tx interval doubles battery life doubles
Critical Point Algorithm
72
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
Min Max Avg.
5th
percentile
25th
percentile
50th
percentile
68th
percentile
95th
percentile
Total Critical Point Count 2 322 35 3 13 27 38 97
Total GPS Fix Count 20 3,710 193 31 74 130 188 511
% Savings 20.83% 99.40% 77.43% 47.97% 69.49% 80.00% 86.83% 95.84%
Bytes Saved* 595 403,172 18,883 2,380 6,426 12,138 17,493 54,788
Distance Critical Points (m) 0.00 1,043,805.50 7,437.09 328.14 1,162.37 2,675.00 4,049.37 22,815.61
Total Distance (m) 2.36 1,087,043.20 7,878.02 380.79 1,252.55 2,913.39 4,345.91 24,231.34
Distance Error Percentage 0.00% 100.00% 8.90% 1.94% 3.98% 6.20% 8.70% 24.11%
* Based on 119 bytes per UDP payload

73. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept.
2011, doi:10.1109/MPRV.2010.48 © 2011 IEEE
IEEE Communications Magazine, Vol. 44, No. 11, pp. 156-163, November 2006.
© 2006 IEEE
IEEE Network Magazine, Vol.24 No.4, July 2010. © 2010 IEEE
73
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

74. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
LAISYC Protocol Choices
Application
Data
74
Layered Networking Model
Location
Data
TCP
(Transport Layer)
HTTP
(Application Layer)
SOAP
(using XML tags)
UDP
(Transport Layer)

75. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
POST /busstoparrival/busstopws.asmx HTTP/1.1
Host: 73.205.128.123
Content-Type: text/xml; charset=utf-8
Content-Length: length
SOAPAction: "http://tempuri.org/GetNextNVehicleArrivals"
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
<GetNextNVehicleArrivals xmlns="http://tempuri.org/">
<n>int</n>
<RouteID>int</RouteID>
<DirectionCodeID>int</DirectionCodeID>
<BusStopID>int</BusStopID>
<TripID_External>string</TripID_External>
</GetNextNVehicleArrivals>
</soap:Body>
</soap:Envelope>
SOAP Request via HTTP
GET
/busstoparrival/busstopws.asmx/GetNextNVehicleArrivals?
n=string&RouteID=string&DirectionCodeID=string
&BusStopID=string&
TripID_External=string HTTP/1.1 Host: 73.205.128.123
HTTP-POST Request
• 3.7 times more characters using
SOAP!
• Plus, many mobile platforms
don’t natively support SOAP
• Java ME
• Android
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
75
1. App Data - SOAP vs. HTTP

76. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
76
7.02
12.68
16.76
19.37
9.44
17.77
18.62
24.01
0
5
10
15
20
25
30
4 15 30 60
BatteryLife(hours)
Interval Between Wireless Transmissions (s)
Using HTTP Increases Battery Life by 28% on Avg.
JAX-RPC HTTP-POST
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
SOAP
1. App Data – SOAP vs. HTTP

77. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
77
0
0.05
0.1
0.15
0.2
0.25
0.3
1
16
31
46
61
76
91
106
121
136
151
166
181
196
211
226
241
256
271
286
PowerConsumption(W)
Elapsed Time (sec)
Energy Consumption of TCP vs. UDP
(a)Wireless TransmissionEvery 4 seconds
TCP
UDP
At 4 sec, TCP and UDP consume around the same power
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions
2. Location Data - TCP vs. UDP

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78
1
9
17
25
33
41
49
57
65
73
81
89
97
105
113
121
129
137
145
153
161
169
177
185
193
201
209
217
225
233
241
249
257
265
273
281
289
297
Elapsed Time (sec)
EnergyConsumption of TCP vs. UDP
(a)Wireless TransmissionEvery 10 seconds
TCP UDP
PowerConsumption(W)
 At 10 sec, TCP consumes approx. 38% more power than UDP
 UDP = avg. 3.68 joules/transmission
 TCP = avg. 5.08 joules/transmission
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

79. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Demonstration of architecture through innovative apps
79
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

80. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Apps implemented using LAISYC
 LAISYC has been used to implement two innovative
mobile apps
 TRAC-IT – simultaneous multimodal travel behavior data
collection and real-time traffic alerts
 Travel Assistance Device (TAD) – real-time transit
navigation to help riders with intellectual disabilities
 LAISYC modules provide key benefits that make apps
possible:
 High-resolution real-time GPS tracking
 Significantly increased battery life
 Reduced data communication between phone and server
80

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Example benefits of LAISYC
81
GPS Sampling Real-time server
communication
Encryption Battery Life
TRAC-IT 4 s 8.04 hrs
TRAC-IT 4 s UDP packet loss =
2.7%
4.21 hrs
TRAC-IT w/
LAISYC
Dynamic
(4 s moving,
300 s stopped)
Adap. Loc. Data Buff.
UDP packet loss =
0.54%
HTTPS - SSL
UDP - 128-bit AES
15.44 hrs
Avg, n = 1857n = 2,642,309
 2011 USDOT-sponsored TRAC-IT deployment
 30 users with Sanyo Pro 200 phones on Sprint network
 Over 4 million GPS data points collected during ~2 months
n = 46,785

82. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
The Contributions of LAISYC to the State-of-the-Art of
Location-Aware Mobile Applications
82
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

83. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Contributions of research (A)
 A modular software architecture that is:
 Intelligent, dynamic, and efficient – balances real-time
requirements with limited device resources:
 Reduces battery energy footprint
 Reduces data communications with server
 Supports real-time applications
 Device-based modules
 Supports high-precision and high-accuracy positioning
systems (GPS)
 Fully implementable by 3rd party mobile app developers
 Uses existing mobile device APIs
83
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

84. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Contributions of research (B)
 Experimental results that validate architecture
components
 Quantitative results from real devices and real GPS data
 Defined methodologies to select threshold values
 Innovative apps that demonstrate utility of LAISYC
 TRAC-IT – simultaneous real-time travel behavior data
collection with real-time location-based services
 TAD – real-time transit navigation that alerts the user
when to exit the bus
 Observation - Importance of contributions continues to
increase with evolving mobile hardware
84
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

85. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Future Work
 GPS Auto-Sleep
 Kalman filter addition to increase mean state accuracy
from 88.4% to 92%
 Memorize sleep locations, rather than wait for timeout
 Resolve GPS periodic sampling issues in Android
 Location Data Buffering
 Using Critical Point Algorithm to determine TCP
transmissions
 New LAISYC modules:
 Position Estimation
 Privacy Filter
85

86. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Permissions and Notices
 We have been successful in publishing and presenting our
research in a variety of peer-reviewed venues:
 6 issued U.S. patents
 11 pending U.S. and international patents
 8 journal publications
 9 conference proceeding publications
 56 conference presentations
 We have obtained permission from IEEE, Transportation
Research Board, Journal of Navigation, Institution of
Engineering and Technology, Intelligent Transportation
Systems (ITS) Word Congress, and ITS America to reprint
published content
 Various technologies licensed to DAJUTA, LLC in 2010
86

87. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Publications –
Journals
1. "A Location-Aware Framework for Intelligent Real-Time Mobile Applications," IEEE Pervasive Computing, vol.
10, no. 3, pp. 58-67, July-Sept. 2011.
2. “Positional Accuracy of Assisted GPS Data from High-Sensitivity GPS-enabled Mobile Phones,” The Journal of
Navigation, volume 64, issue 03, pp. 381-399. July 2011.
3. “Global Positioning System Integrated with Personalized Real-Time Transit Information from Automatic Vehicle
Location,” Transportation Research Record: Journal of the Transportation Research Board, Transit 2010 Vol
1, No. 2143, pp. 168-176, October 2010.
4. “G-Sense: A Scalable Architecture for Global Sensing and Monitoring”, IEEE Network Magazine, Vol.24
No.4, July 2010.
5. “Automating Mode Detection for Travel Behavior Analysis by Using GPS-enabled Mobile Phones and Neural
Networks,” Institution of Engineering and Technology (IET) Intelligent Transportation Systems, 2010, Vol. 4, Iss.
1, pp. 37–49. doi: 10.1049/iet-its.2009.0029. © The Institution of Engineering and Technology 2010.
6. “Location API 2.0 for J2ME – A New Standard in Location for Java-enabled Mobile Phones,” Computer
Communications, Volume 31, Issue 6, pp. 1091-1103, 18 April 2008. doi:10.1016/j.comcom.2008.01.045.
7. “The Travel Assistance Device: Utilizing GPS-enabled Mobile Phones to Aid Transit Riders with Special Needs,”
Institution of Engineering and Technology (IET) Intelligent Transportation Systems, 2010, Vol. 4, Iss. 1, pp. 12–
23. doi: 10.1049/iet-its.2009.0028. © The Institution of Engineering and Technology 2010.
8. “A General Architecture in Support of Interactive, Multimedia, Location-based Mobile Applications”, IEEE
Communications Magazine, Vol. 44, No. 11, pp. 156-163, November 2006.
87

88. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Publications –
Conference Proceedings
88
1. “TAD – Travel Assistance Mobile App to Help Transit Riders,” Proceedings of the 2011 ITS World Congress, Orlando, FL, October
18, 2011.
2. “From Idealism to Realism: Lessons Learned from Development of Standards-Based Software for Advanced Public
Transportation Systems,” Proceedings of the National Academy of Sciences’ Transportation Research Board 90th Annual
Meeting, Paper #11-2254. January 24, 2011. Paper #11-2254.
3. “Evaluating the Deployment of a Mobile Navigation Device at Four Transit Agencies in Florida,” Proceedings of the National
Academy of Sciences’ Transportation Research Board 90th Annual Meeting, Paper #11-2213. January 24, 2011.
4. “Integration of GPS-Enabled Mobile Phones and AVL: Personalized Real-Time Transit Navigation Information on Your Phone,”
Proceedings of the National Academy of Sciences’ Transportation Research Board 89th Annual Meeting, Paper # 10-2571.
Washington, D.C., January 12th, 2010.
5. “TRAC-IT: A Software Architecture Supporting Simultaneous Travel Behavior Data Collection and Real-Time Location-Based
Services for GPS-Enabled Mobile Phones,” Proceedings of the National Academy of Sciences’ Transportation Research Board 88th
Annual Meeting, Paper #09-3175. January, 2009.
6. “The Travel Assistant Device: Utilizing GPS-Enabled Mobile Phones to Aid Transit Riders with Special Needs,” 15th World
Congress on Intelligent Transportation Systems, New York, New York, November 16-20, 2008. Paper # 30429.
7. “Real-time Travel Path Prediction using GPS-enabled Mobile Phones,” 15th World Congress on Intelligent Transportation
Systems, New York, New York, November 16-20, 2008. Paper # 30413.
8. “Trac-It - A ‘Smart’ User Interface For A Real-Time, Location-Aware, Multimodal Transportation Survey,” 15th World Congress on
Intelligent Transportation Systems, New York, New York, November 16-20, 2008. Paper # 30153.
9. “Dynamic Management of Real-Time Location Data on GPS-enabled Mobile Phones,” Proceedings of IEEE UBICOMM 2008 – The
Second International Conference on Mobile Ubiquitous Computing, Systems, Services, and
Technologies, Valencia, Spain, September 29 – October 4, 2008.

89. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Issued U.S. Patents
1. U.S. Patent # 8,036,679 – Optimizing performance of
location-aware applications using state machines. Issued
March 20, 2012, U.S. Patent and Trademark Office.
2. U.S. Patent # 8,045,954 – Wireless Emergency-Reporting
System. Issued March 20, 2012, U.S. Patent and Trademark
Office.
3. U.S. Patent # 8,145,183 - On-Demand Emergency Notification
System using GPS-equipped Devices. Issued March 27, 2012,
U.S. Patent and Trademark Office.
4. U.S. Patent # 8,138,907 – Travel Assistant Device. Issued
March 20, 2012, U.S. Patent and Trademark Office.
5. U.S. Patent # 8,169,342 - Method of Providing a Destination
Alert to a Transit System Rider. Issued May 1, 2012, U.S.
Patent and Trademark Office.
89

90. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Acknowledgements
 My major professors, Dr. Rafael Perez & Dr. Miguel
Labrador, for their mentoring, patience, and
guidance throughout my untraditional doctoral
journey
 My committee:
 Dr. Rafael Perez
 Dr. Miguel Labrador
 Dr. Hyun Kim
 Dr. Thomas Weller
 Dr. Dewey Rundus
 Dr. Tapas Das, Chair
90
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

91. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Acknowledgements
 Phil Winters, for his trust and supervision as I built my
research career
 Nevine Georggi, Ed Hillsman, and rest of the TDM Team
for their support and collaborations
 CUTR Management, for their support of our many
research projects
 REU and graduate students who contributed to our
research:
 Alfredo Perez, Isaac Taylor, Marcy Gordon, Khoa Tran, Leon
Augustine, David Aguilar, Josh Kuhn, Ismael Roman, Oscar
Lara, Narin Persad, Dmitry Belov, Jeremy Weinstein, Paola
Gonzalez, Tiffany Burrell, Francis Gelderloos, Joksan
Flores, Jorge Castro, Richard Meana, Theo Larkins, Hector
Tosado, Marcel Munoz
91
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

92. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
And support from:
 National Center for Transit Research
 Florida Department of Transportation
 US Department of Transportation
 National Science Foundation
 Sprint-Nextel Application Developer Program
92
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

93. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Thank You to Family and Friends!
 This is dedicated to Carlene, my wonderful wife, for
her undying faith, hope, love, encouragement, and
belief in me, and Zach, my new son
 To my family - Mom and Dad, my brother Ryan and
sister-in-law Daphna, Momma Brown and Matt
 Everyone else who has supported me
93
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

94. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Questions?
94
Research Associate & Ph.D. Candidate
Center for Urban Transportation Research &
Department of Computer Science & Engineering
University of South Florida
(813) 974-7208
USF Location-Aware Information Systems Lab:
http://www.locationaware.usf.edu/
Sean J. Barbeau, M.S.
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

95. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Extra slides
95

96. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Known LBS Architectures
 Early architectures implemented positioning systems
such as assisted GPS
96
Hardware
(e.g., Qualcomm chipset)
Operating System
(e.g., Linux)
Device Cell Network
Link Layer
(e.g., CDMA IS-95)
Introduction
Known LBS
Architectures
Challenges
Proposed LAISYC
Architecture
Evaluation Conclusions
Carrier Servers
Hardware
(e.g., Intel CPU/Motherboard)
Operating System
(e.g., Linux)
Custom Network Server

97. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Known LBS Architectures
 Next, servers were added to communicate with public
safety access points (PSAPs) for e911
 Not accessible to apps
97
Hardware
(e.g., Qualcomm chipset)
Operating System
(e.g., Linux)
Device Cell Network
Link Layer
(e.g., CDMA IS-95)
Private
Network
PSAP
Introduction
Known LBS
Architectures
Challenges
Proposed LAISYC
Architecture
Evaluation Conclusions
Link Layer
(e.g., Fiber)
Network Layer
(e.g., IP)
Tranport Layer
(e.g., TCP, UDP)
Application Layer
(e.g., HTTP, FTP, VOIP)
Hardware
(e.g., Intel CPU/Motherboard)
Operating System
(e.g., Linux)
Custom PSAP Server

98. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
My focus – Mobile LAISYC platform
 There have been other contributors to our research
 I have implemented ~96% of mobile LAISYC
platform/test code in Java over ~7 years
98
19,940
893
LAISYC Device-side
Lines of Code
Barbeau
Others
5,139
9,905
LAISYC Server-side
Lines of Code
Barbeau
Others
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

99. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
U.S. Patent # 8,036,679 – Optimizing performance of location-aware
applications using state machines.
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011. © 2011
IEEE
Proceedings of IEEE UBICOMM 2008 – The Second International Conference on
Mobile Ubiquitous Computing, Systems, Services, and
Technologies, Valencia, Spain, September 29 – October 4, 2008. © 2008 IEEE
The Journal of Navigation, volume 64, issue 03, pp. 381-399. July 2011. © 2011
The Royal Institute of Navigation.
99
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

100. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
 stopped_speed_threshold = 1 m/s
 95th percentile of horizontal error
 high_speed_threshold = 1.5 m/s
 98th percentile of horizontal error 100
0.00
3.25
0.36
0.25
0.5
1
1.435
1.5925
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
Min Max Avg 50th
percent.
68th
percent.
95th
percent.
98th
percent.
99th
percent.
Speed(m/s)
Speed Error
GPS Speed Observations When Stationary Indoors
(n = 165, recorded over 5.5 hours)

101. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
GPS Auto-Sleep
101
Device GPS Type
Sample
Size
Min Max Avg 50th 68th 95th RMSE
Motorola i580 Assisted 478 0.74 90.69 15.16 9.78 15.15 47.9 21.64
Sanyo 7050 Assisted 1513 0.16 32.04 8.78 6.23 9.33 24.44 11.33
Horizontal Error Statistics (meters)
Motorola i580
Sanyo 7050
True Location
 moved_distance_threshold = 100 m
 Based on max. observed
horizontal error of 90.69 m

102. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
102
 high_horizontal_accuracy_threshold = 80 m
 Based on max. observed hor. acc. of 58 m
GPS Auto-Sleep

103. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept.
2011, doi:10.1109/MPRV.2010.48 © 2011 IEEE
The Journal of Navigation, volume 64, issue 03, pp. 381-399. July 2011. ©
2011 The Royal Institute of Navigation.
Proceedings of IEEE UBICOMM 2008 – The Second International
Conference on Mobile Ubiquitous Computing, Systems, Services, and
Technologies, Valencia, Spain, September 29 – October 4, 2008. © 2008
IEEE
103
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

104. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Critical Point Algorithm
104
Critical Point Evaluation Sliding Window
Non-critical Point (discarded)
Last Critical Point
Current Point
[ ] [ ] [ ]
Last Trigger Point (Under Evaluation)

105. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Critical Point Algorithm
105
Critical Point Sliding Window Memory Requirements
Non-critical Point (discarded)
Last Critical Point
Current Point
[ ] [ ] [ ]
Last Trigger Point (Under Evaluation)
[ ] [ ] [ ]
Iteration X Iteration X+1 Iteration X+2
[ ] [ ] [ ]

106. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Critical Point Algorithm
106
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Min Max Avg 20th
percent
25th
percent
50th
percent
68th
percent
95th
percent
Std dev
Speed(meterspersecond)
Outdoor Walking GPS Speed
n = 53
 min_speed_threshold = 0.1 m/s
 Based on walk speed 25th percentile of 0.2 m/s, 20th percent. of 0 m/s

107. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
 When comparing a) all points to b) critical points using a min_speed_threshold of
0.1 meters per second, the general walking path of the user is preserved, with some
filtering at the beginning of the trip (bottom left of each image)
107
a)
b)

108. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
 Over 97% of the GPS drift shown here at an indoor stationary location can be filtered
out by the Critical Point Algorithm when using a 0.1 meters per second
min_speed_threshold
108
Min
Speed
Number of
Critical Points
Total Number
of Points % Savings
Bytes
Saved*
Walking 0 50 53 5.66% 357
0.1 39 53 26.42% 1,666
Min
Speed
Number of
Critical Points
Total Number
of Points % Savings
Bytes
Saved*
Stationary 0 904 3519 74.31% 311,185
0.1 91 3519 97.41% 407,932
*Based on 119 bytes per UDP payload

109. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Critical Point Algorithm
109
Possible true position when sampled
Sampled GPS position
Estimated horizontal accuracy (68th
percentile by Java ME specification)
Possible true path
Observed Path

110. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Funded by:
• National Center for Transit Research
• US Department of Transportation
• Florida Department of Transportation
110
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

111. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
TRAC-IT
 Created for
bus, bike, walk, car travel
data collection
 Passive and Active modes
 Simultaneous location-
based services as incentive
111
TRAC-ITTRAC-IT
<- Back Select
(1) Work Related
(2) Shopping
(3) Pickup
Someone
(4) Go Home
etc. ...
Purpose of Trip:

112. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
TRAC-IT Deployment
112
Date Range 2/10/2011 to 4/29/2011
Total Number of Users 30
Total Number of Sessions 1,857
Avg. Session Length (hrs) 15.44
Total Survey Time (days) 1,194.80
Avg. Survey Time per User (days) 39.83
Total Number of GPS fixes Received 4,023,917
Avg. Number of GPS fixes per Session 2,166.89
Avg. Number of GPS fixes per User 134,130.57
TRAC-IT Data Collection for USDOT-funded project
 2011 USDOT Value Pricing project in Tampa, FL
 30 participants, 40 days avg. per participant
 4,023,917 GPS fixes, 1,633 processed trips

113. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
TRAC-IT Deployment Analysis
 95% of 899 sessions had less than 3.95% of lost UDP
packets
 Average session length was 15.44 hrs
 (Avg. battery life was at least this long)
113
# Lost Per Session % Lost Per Session
Min 0 0.00%
Max 290 66.15%
Avg 15.67 1.19%
50th percentile 8 0.48%
68th percentile 13 0.88%
95th percentile 59.15 3.95%
UDP and Location Data Buffering - Packets Lost

114. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Funded by:
• National Center for Transit Research
• US Department of Transportation
• Florida Department of Transportation
• Transportation Research Board (TRB) IDEA program
114
Introduction
Known LBS
Architectures
Limitations
Proposed LAISYC
Architecture
Evaluation Conclusions

115. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Travel Assistance Device
115
 Transit navigation app - Assists transit riders with intellectual
disabilities by telling them when to exit the bus in real-time

116. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
Travel Trainers Plan trips via TAD website
116

117. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
TAD Mobile App Interface
 TAD cell phone app tells the traveler to “Get Ready” and “Pull
the Cord Now!” when it is time for them to exit the bus.
 Prompts are visual, auditory, and tactile.
117
TADTAD
Cancel Select
Select Trip
(1) Home to Work
(2) Work to Home
(3) Home to Movie
Work to HomeWork to Home
Back #
Distance to Final Stop:
5.6 miles
18 Livingston West
TADTAD
OK
Pull the Cord Now!
(+Sound and Vibration)

118. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
TAD Bus Stop Detection Algorithm
 Multiple iterations of algorithm after field tests
 2 U.S. patents issued on final version, TAD system
118
Second-to-Last
Stop
Transit Vehicle
Direction
“Pull the Cord Now” Alert Location
Legend
Destination Stop
Second-to-Last
Stop
Transit Vehicle
Direction
Zone2 Departure Check:
If ((Zone1Arrival = true ||
Zone1Departure = true) &&
(Device in Zone 2) )Then
Trigger “Pull Cord Now
Get Ready Check:
If (Device within W meters of 2nd
to Last Stop) Then
Trigger “Get Ready”
Destination Stop
Y
X

119. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
TAD Analysis
 Collaboration with Florida Mental Health Institute
 33 trials with 3 individuals with moderate mental
retardation (TAD = 100% accuracy for alerts)
 Riders only requested stop and exited bus at correct
location when TAD alerted was used
119
0
1
2
1 2 3 4 5 6 7 8 9 10 11
StepsCompleted
Trials
Baseline With TAD Baseline With TAD

120. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
LAISYC Publications (A)
Session Management
 IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011, doi:10.1109/MPRV.2010.48
 IEEE Communications Magazine, Vol. 44, No. 11, pp. 156-163, November 2006.
 IEEE Network Magazine, Vol.24 No.4, July 2010.
GPS Auto-Sleep
 IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011, doi:10.1109/MPRV.2010.48
 The Journal of Navigation, volume 64, issue 03, pp. 381-399. July 2011. (C) 2011 The Royal Institute of Navigation.
 Proceedings of IEEE UBICOMM 2008 – The Second International Conference on Mobile Ubiquitous
Computing, Systems, Services, and Technologies, Valencia, Spain, September 29 – October 4, 2008.
 U.S. Patent # 8,036,679 – Optimizing performance of location-aware applications using state machines.
Critical Point Algorithm
 IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011, doi:10.1109/MPRV.2010.48
 The Journal of Navigation, volume 64, issue 03, pp. 381-399. July 2011. (C) 2011 The Royal Institute of Navigation.
 Proceedings of IEEE UBICOMM 2008 – The Second International Conference on Mobile Ubiquitous
Computing, Systems, Services, and Technologies, Valencia, Spain, September 29 – October 4, 2008.
Adaptive Location Data Buffering
 IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011, doi:10.1109/MPRV.2010.48
Location Data Encryption
 IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011, doi:10.1109/MPRV.2010.48
Location Data Signing
 IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011, doi:10.1109/MPRV.2010.48
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121. Protected under U.S. Patents #8036679, #8045954, #8140256, #8145183, #8169342, Other Patents Pending USF 2012
LAISYC Publications (B)
TRAC-IT
 IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011, doi:10.1109/MPRV.2010.48
 15th World Congress on Intelligent Transportation Systems, New York, New York, November 16-20, 2008. Paper # 30153.
 Proceedings of the National Academy of Sciences’ Transportation Research Board 88th Annual Meeting, Paper #09-3175.
January, 2009.
 15th World Congress on Intelligent Transportation Systems, New York, New York, November 16-20, 2008. Paper # 30413.
Travel Assistance Device (TAD)
 IEEE Pervasive Computing, vol. 10, no. 3, pp. 58-67, July-Sept. 2011, doi:10.1109/MPRV.2010.48
 15th World Congress on Intelligent Transportation Systems, New York, New York, November 16-20, 2008. Paper # 30429.
 Proceedings of the National Academy of Sciences’ Transportation Research Board 89th Annual Meeting, Paper # 10-2571.
Washington, D.C., January 12th, 2010.
 Transportation Research Record: Journal of the Transportation Research Board, Transit 2010 Vol 1, No. 2143, pp. 168-
176, October 2010.
 Institution of Engineering and Technology (IET) Intelligent Transportation Systems, 2010, Vol. 4, Iss. 1, pp. 37–49. doi:
10.1049/iet-its.2009.0029. © The Institution of Engineering and Technology 2010.
 Proceedings of the 2011 ITS World Congress, Orlando, FL, October 18, 2011.
 Proceedings of the National Academy of Sciences’ Transportation Research Board 90th Annual Meeting, Paper #11-2254. January
24, 2011. Paper #11-2254.
 Institution of Engineering and Technology (IET) Intelligent Transportation Systems, 2010, Vol. 4, Iss. 1, pp. 12–23. doi:
10.1049/iet-its.2009.0028. © The Institution of Engineering and Technology 2010.
 Proceedings of the National Academy of Sciences’ Transportation Research Board 90th Annual Meeting, Paper #11-2213. January
24, 2011.
 U.S. Patent # 8,138,907 – Travel Assistant Device.
 U.S. Patent # 8,169,342 - Method of Providing a Destination Alert to a Transit System Rider
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