The prospect of coupling social computing with sensing capabilities of current mobile devices makes it possible to provide social applications with higher degrees of context-awareness, detection of activities of individuals and groups, as well as implicit social interaction through sharing of context-sensitive information. In addition to the pervasive context obtained from the mobile devices, the links and user interactions in social networks can be regarded as rich sources of information for pervasive applications. In this paper we present Mobile Social Gateway (MoSoGw), a web service that provides a generic interface for optimized information transfer between mobile devices and different social networks, as well as third-party web services. Its interface is generic in that it makes transparent to the mobile client application the interaction with social networks and web services. Performance and scalability were major concerns when designing and implementing MoSoGw. Hence, its architecture and all technologies used in its development have been carefully chosen so as to scale to large numbers of clients and support high volume of concurrent requests. --- M-MPAC '11 Proceedings of the Third International Workshop on Middleware for Pervasive Mobile and Embedded Computing

1. 1
A Web Service for Flexible Integration
of
Mobile Applications with Social
Networks
Victor Pantoja and Markus Endler
PUC-Rio, Brazil

2. 2
Technical advances of mobile technologies and Web have
promoted new forms of social interactions
Motivation
»
Mobile Social Software (MoSoSo) made social connectivity even
more explicit:
»
· Extends interpersonal to network interactions through the many-
to-many communication paradigm of online social networks.
Virtual and physical worlds are rapidly growing together:»
· Online social networks are increasingly used for
interaction
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3. 3
Motivation
Current MoSoSo has usually no support for uniform and extensible
interaction with online social networks, other web services and
mobile middleware systems for context processing.
»
Inefficient transfer of information:»
· Amount of data transferred
· Higher consumption of wireless bandwidth and battery
· Example: Google Maps API
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4. 4
ss
Motivation - Scenario
4
Academic Car Sharing Network
Prof. Paul
UniRio Campus
Student Anna

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Motivation - Scenario
5
UniRio Campus
Academic Car Sharing Network
Prof. PaulStudent Anna
Pervasive Context:
Location, speed, userID
Pervasive Context:
Location, userID
Social Context:
Anna and Paul have common
acquaintaces

6. 6
Mobile Social Gateway
Provides a generic interface for optimized information transfer
between mobile devices and social networks or other web
services
»
» Allows third-party Web services to subscribe for a specific
context information
» Performance and scalability were major concerns
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7. 7
Architecture
Prototype
Performance
Conclusion
Agenda
1
2
3
4
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8. 8
Architecture of MoSoGw
MoSoGw is responsible for filtering, caching and distributing
context data from the mobile device to social networks and vice-
versa
»
The primary goals of MoSoGw are:»
· Minimize the amount of data transferred
· Allow for some kind of processing of the pervasive and social
context data
· Provide a uniform interface to the social networks
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9. 9
Architecture of
MoSoGw
SN: Social Network
WS: Web Service
CMS: Context Management
System
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Architecture of MoSoGw
nginx HTTP server:»
· Event-driven architecture
· Asynchronous non-blocking I/O
· disk cache
Tornado:»
· lean Python framework
· high performance
· non-blocking I/O
Each component was chosen
in order to achieve high
performance:
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memcached: memory cache»

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APIs
11
Android Java API»
· better suited to mobile app developers
· details are hidden behind the Java class abstraction
Allows client applications and third-party web services to be built
by using any platform/environment
»
REST API:»
· applications must know MoSoGw interfaces and URLs

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Prototype
Mobile Social Share:»
· Allows mobile users to share context information about their
position
· Estimates traffic conditions based on users’ velocities
· Twitter, Facebook and 3rd Party Apps
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Prototype
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Prototype
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Performance Evaluation
Ubuntu 10.04 with 512MB RAM»
»Simple MoSoGw box:
· 1 nginx instance
· 1 Tornado instance
· 1 MySQL Server
All the three cache layers described were implemented»
Scenario:»
1 - Create a new user
2 - Log in with a user
3 - Send an invitation to another user
4 - Send context information to Twitter15

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Performance
Evaluation
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Performance
Evaluation
Peak of 4.45s but it is quite reasonable to assume that users can wait
4.45s to get a context information update17
Average: 0.177s

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Conclusion
MoSoGw facilitates integration with social networks»
It enables third-party web services to process or match users’
context information and social network data
»
Initial usage and performance tests are non-conclusive»
MoSoGw has some promising architectural features.»
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· makes it transparent for developers

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Future Work
Parallel/distributed deployment MoSoGw and precisely assess its
scalability
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Future Work
Better exploring integration with third party apps
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Thank You!
victor.pantoja@gmail.com
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