3. 3
Petrozavodsk, Apr 2013
Location Based Services
● LBS = using geographical context
– Indoor services
– Mobile healthcare
– City information
● Transport
● Traffic
● ...
4. 4
Petrozavodsk, Apr 2013
Geo-tagging
● Def: the process of adding geographical
identification metadata to various media:
– Photo, video
– Web-pages,
– SMS, QR-codes
– files
5. 5
Petrozavodsk, Apr 2013
Terminology
● Tag – tuple <t, L, B, H, data>,
– t – time
– B,L,H – coordinates
– data – text data ~1K
● Channel – classifier for group of tags
6. 6
Petrozavodsk, Apr 2013
Main features of tagging system
● Access to tags
● Classification
● Filtering
● Session and User management
● Massive data processing
7. 7
Petrozavodsk, Apr 2013
Features
● Current
– Basic geo-tagging
– Plain and spacial filtration
– Load balancing across Databases and web
servers
● Will be published in 2013
– Exporters (wikimapia, google maps, OSM,
4square)
– Channel aggregation
– Multi-service databases
9. 9
Petrozavodsk, Apr 2013
Channels and tags
LBS Platform
Канал
Channel
Channel
Channel
Channel
Tag
- time
- coordinates
- data (link)
Filtration
- time
- radius
- figure (2D or 3D)
Tag
Tag
Tag
10. 10
Petrozavodsk, Apr 2013
Geo2tag architecture
Queryengine
Session manager
HP
database
BLOBs
cache
Indexer
Cluster/cloud
infrastructure
backend
clients
Libraries:
jgeo, http_reqs
Session cache
web
android
web
Qt-based
embedded
JSON
System cache
11. 11
Petrozavodsk, Apr 2013
Resources
● Main site http://geo2tag.org
● Tracker https://geo2tag.atlassian.net/
● Sources https://github.com/OSLL/geo2tag
● Support: geo2tag-support@osll.spb.ru
● CI server: pulse.geo2tag.org
12. 12
Petrozavodsk, Apr 2013
JSON/REST API
Command:
– Service URL
– Function
– Parameters
Example
http://debug.geo2tag.org/service?{json}
– Json: '{"login":"User","password":"pwd@"}
13. 13
Petrozavodsk, Apr 2013
RESTful API
● REST = Representational State Transfer
– 2000 by Roy Fielding
– The model of http (v 1.0)
– HTTP POST is being used for
communication.
14. 14
Petrozavodsk, Apr 2013
Goals of REST
● Scalability of component interactions
● Generality of interfaces
● Independent deployment of components
● encapsulate legacy systems
15. 15
Petrozavodsk, Apr 2013
Java script Object Notation
● Text-based, Object-oriented, data
interchange format.
● Structure:
– A collection of name/value pairs
– Ordered list of values.
18. 18
Petrozavodsk, Apr 2013
Geo2tag REST API
Based on JSON objects interchange
● Command:
– URI
● Service URL
● Function
– Parameters: JSON object
Example
URI http://debug.geo2tag.org/service/login
– Params (Json): '{"login":"User","password":"test"}