Sistemi Mobili e Pervasivi

Uniplaces:Progetto per il corso “Sistemi Mobili e Pervasivi”

A.A. 2012/2013

Docenti:Prof. Avvenuti MarcoIng. Vecchio Alessio

Candidato:Enrico D'Urso

UniPlaces Requirements

Functional Requirements:

● UniPlaces MUST be an instant messaging service

● Sending messages MUST be 'location based' and relative to a topic (Multicast Messaging)

● Unicast messaging MUST also be possible (no need user's phone number )

Non Functional Requirements:

● User localization MUST be accurate

● Uniplaces MUST be reliable

● UniPlaces MUST be careful to power saving

● UniPlaces MUST allow the user to do what he likes (this involves numerous other functional requirements)

What UniPlaces uses to meet requirements

● UniPlaces uses GCM (Google Cloude Messaging ), a Google service that helps developers send data from servers to their Android applications (Push Notification).To send messages, a third party is needed, a Server Web.

● To meet localization requirements GPS Service is used

● To minimize battery usage some parameters are used (further details in other slide)

● To meet user need, some 'social network pattern' are used (profile with photo, judgment of the messages, add contacts, read old conversations ... )

UniPlaces: Home Activity

How UniPlaces works: Reg Phase

Id Req

Id registration

Id registration

System needs a web server with Database:1: Phone makes a request to join GCM service (reliable service)2: GCM returns an unique ID3: Phone forwards this information to WebServer that stores this information in the Database

How UniPlaces works: Localization phase

ID, GPS coord.

This phase can be repeated several times, depending on the user mobilityand the options of energy saving

How UniPlaces works: Messaging phase

ID, Message

ID, [Id dst][Center GPS coord,Radius ] , Message

ID, Message

Unicast Locat. basedSender id

Payload

If needed, Server Computes ID of the receivers

Energy saving

Update location from GPS service is costly

User can (indirectly) choose update frequency

Energy saving

Update location from GPS service is costly

User can (indirectly) choose update frequency

Code:

requestLocationUpdates( minTime, minDistance, …)

UniPlaces can not use coarser location criteria, accuracy is a non functional requirement.

GPS Drawback: indoor environment

Solutions:

● Saving last user location (to be improved exploiting user daily routine, e.g.: mapping hours of day to user location )

● Google wifi location database

Future Work: Uniplaces 2.0

➔Reduce memory consumption and battery

➔Decouple virtual position, from the physical, i.e: User can choose any location manually

➔Improve GUI (In phase test it has not been satisfactory judged )