Indoor Positioning System for Android

1. EETAC App
A new revolutionary software for EETAC’s
students and teachers.
This App comes with localization, routing
mechanisms, social network and much more!

2. 1. Concept Introduction to the
2. How it works? Stories application and user
experience
3. Workflow
4. Entity-Relashionship Diagrams with different
aspects of the architecture of
5. Technologies
Table of Contents
the application.
6. Ericsson Maps
7. Security Most important technical
aspects, explained in
8. Rest Client Pattern detail.
9. Cache mechanism
10. Traffic Analisys
11. Summary & Conclusions
2

3. Explaining what offers our
App
3

4. » Offers orientation service inside the campus, where the
user can explore the buildings and find the best route to
go to any room.
» Follows web 2.0  Users can enrich the App sending
comments and P.O.I
» Userful tool designed for Eetac students and teachers
but also for visitors which don’t know the campus.
» What is the difference with Foursquare and other
similar apps? Indoor positioning and routing.
Concept 4

5. Giving an example of how
the App works
5

6. » This Monday was about to start badly for Bob. Just landing from
London at 13:17 am, he could definitively not remember the
explications about how to reach the conference room. Luckily, he
downloaded EetacApp before leaving, following his colleague’s
advice. Within a few moments, the application gave him the
quickest way to the place.
» After the presentation of Urbanization in room V-212, the group
was very pleased to see their friends have already taken pictures
and upload them with the EETAC App, creating several threads
about the main debated issues. Now, other students can see the
gallery pictures and add some comments.
Story 6

7. Explaining the Flow
Diagram of the layouts of
our App
7

8. Local registration
Starting Point Login (general)
Twitter login
Flow Diagram for Authentication 8

9. Starting Point Explore Sites Site Site P.O.interest
Profile (everywhere)
ActionBar
Map
Flow Diagram for general use 9

10. Understanding the Entity-
Relationship diagram
10

11. 6 entities Location
1 1
» Location: Where is the user 0..*
1
(dynamic)? User -id
Site
-id -name
-username -description
Where is a Site (static)? -password
-surname
Table: user_checkin
(user_id | checkin_id) Check-in
Table: site_checkin -num_checkins
(site_id | checkin_id) -num_comments
-description -id -floor
-email 1 0..* -date 0..* 1 -building
» User: User information. -set<Checkin>
-set<Comment>
-site -checkin_id
-route_image
-user
-set<Picture> -set<Picture>
-set<Checkin>
» Site: Site information.
1
1
1 Table: site_picture
» Check-in: Relates a User with (site_id | picture_id)
0..*
Comment Picture
a Site (dynamic). Table: user_comment
(user_id | comment_id) -id
0..* 1
-id
-text Table: picture_comment -author
0..*
-author (picture_id | comment_id) -route_image
» Picture: P.O.I related with a -date
-user
-user
-date
-picture -set<Comment>
Site and a User.
Table: user_picture
(user_id | picture_id)
0..*
» Comment: Comment related
with a Site and a User.
Entity-Relationship Diagram 11

12. Citing all the Technologies
used for the project
12

13. Indoor possitioning
Show maps
HTTP/JSON
OAUTH
Route calc.
HTTP/JSON
REST
Mobile App
Web Server
Database
TCP/IP
Technologies Diagram 13

14. Explaining what the App do
with Ericsson Maps API
14

15. » Create maps using bulging plan and XML tags.
» Indoor localization and navigation using predefined
routes, Wi-Fi Aps localization and XML tags as elevators
or stairs.
Ericsson Maps API 15

16. » Add information using over lays
» Room labels
» Finish flag
» Google Maps to Ericsson Indoor
Maps by Zoom
Ericsson Maps API 16

17. Adding Security to the App
17

18. » Challenge Implemented (SHA) » Token expires in 30min.
» Unique token generation. » For registering purposes, HTTPS
should be used
Eetac_challenge=long ID
GET /date
Eetac_challenge: 63fe6da0... date=”yyyyMMddHHmmssSS”
Eetac_challenge=63fe6da0...
200 OK
date=”2020134…”
token=password=hash(date +
hash(password))=42D11GP... POST /user/login
Eetac_challenge: 63fe6da0…
user
token=password=hash(date +
200 OK or 403 FORBIDDEN hash(password))
user_id=2
If (server_token == client_token) return 200;
Eetac_token=token else return 403;
GET /site
Eetac_token: 42D11GP...
Security for Authentication 18

19. Communicating with the
server through a REST
Client Pattern
19

20. The operating system may shut down the process.
» The processor could be destroyed in the middle of an
operation.
The UI is frozen by the Processor (not interactive).
No memory or Database storage == bandwidth waste.
Wrong REST Client Pattern 20

21. Good REST Client Pattern 21

22. Adding Cache mechanism
to the App
22

23. » Only image caching mechanism implemented
1. Download the image (write the outputstream of HTTP
GET).
2. Save in the SSDcard (cache).
3. Save in memory (SoftReference HashMap)
» Before retrieving all data, retrieve a hashCode of it (no
changes = no hashcode changes = no retrieving all data)
» Save each request in the Content Provider
» Good performance under 1MB of data on the Cursor
Persistence == Requests == Battery consumtion
Cache 23

24. 10
Dimensioning our
App, through a Traffic
Analisys
24

25. γ OFF state
User’s
activity
User’s
Get ALL activity on
Sites site Z
Get
Site Z
Traffic Analisys 25

26. Traffic Analisys 26

27. Traffic Analisys 27

28. What we know: 70ms  Latency for
• Get All Size is a packet of downlink ≈35ms.
length: 3988 + 86 = 4074 •  Unitary discrete time =
bytes. 10ms.
• Minimum packet size for Get
Site Z: 158 + 86 = 244 bytes.
• Estimated velocity at server
output: 1Mbyte/s
 getALL Transmission time
≈ 4ms <35ms
 get Z Transmission time
≈0,25ms << 35ms
• Ping between mobile device
at the Eetac and the server:
Traffic Analisys 28

29. Traffic Analisys 29

30. Traffic Analisys 30

31. JSON Packet size
5000
4000
3000
2000
1000
0
1
10
19
28
37
46
55
64
73
82
91
145
100
109
118
127
136
154
163
172
181
190
199
Series1
Traffic Analisys 31

32. User's Activity
State getALL User's activity getZ
site Z
Time
(ms) 39 18 116 35 23 291 + Time slot = 10ms
 Probability to stay in one state and to leave it
Exhaustive Analysis of the logs: Get the probability to go toward each state.
Traffic Analisys 32

33. State getALL User's activity getZ User's Activity site Z OFF
Probability 8,790000E-08 4,000000E-05 5,130000E-08 1,050000E-04 9,975860E-01
Probability 0,00000879% 0,00400000% 0,00000513% 0,01050000% 99,75860000%
Traffic Analisys 33

34. PDF Session
3.5
3
2.5
2
PDF Session
1.5
1
0.5
0
40 80 120 160 200 240 280 320 360 400 440 480 520 560 600
Traffic Analisys 34

35. Traffic Analisys 35

36. 11
Explain the tasks done; the
tasks to be performed and
the conclusions
36

37. Tasks Performed
» Show EETAC Map (Ericsson)
» Indoor Positioning (Ericsson)
» Route to a Site (Ericsson)
» Twitter Integration (OAuth)
» Server persistence (Postgree + Hibernate)
» REST client and Server communication (Spring and Jersey)
» GET/PUT images from/to the server
» GET/PUT/DELETE comments from/to the server
» PUT/DELETE checkin from/to the server
Tasks performed summary 37

38. Tasks to be Performed
» Interaction between users
» View users profile and comments
» Integration with Facebook
» Add dynamically a Site
» Improve the “Go to” guide
» Use more the Local Cache (Content Provider)
» Integration with Google Maps
Tasks to be performed summary 38

39. Indoor positioning & routing
» Bad precission because of the Aps power. Some brands offer
better precission with their own hard&soft.
Android (Client)
» Since the life cycle of an Activity is managed by Android; the
programmer should be careful.
» Limitted memory space also should be taken into account.
» Battery consumption should be taken into account.
Rest Client Server
» Difficulty to integrate Hibernate (learning curve).
Conclusions 39

40. ? Questions?
40