Architectural Issues in C-A Mobile Apps.

Andrés Fortier1,2, Cecilia Challiol1, Gustavo Rossi1,3, Silvia Gordillo1,4

{andres, ceciliac, gustavo, gordillo}@lifia.info.unlp.edu.ar

Context Aware Group

1LIFIA, Facultad de Informática,UNLP. La Plata, Argentina.2DSIC, Universidad Politécnica de Valencia. Valencia, España.

3CONICET.4CICPBA.

Outline

•Motivation.•Architecture Outline.•Current work.•Conclusions.•Further work.

Motivation: Physical Hypermedia

•Physical Hypermedia (P.H.) applications are a particular kind of context-aware, mobile systems.

•P.H. aim is to enhance real world objects with digital information and links.

•Objects in a P.H. application can be visited in two ways:• Digitally.• Physically.

Physical Hypermedia

Hypermedia

Real World

Physical Hypermedia

•Let’s suppose that the user is in front of La Plata Cathedral.

Hypermedia

Real WorldIt is located in La Plata geographical centre.

Dardo Rocha MuseumCity HallNatural Sciences Museum

La Plata Cathedral

The most outstanding building and monument in the city The magnificence of this Neo Gothic Temple which started being built in XIX Century.

Neo Gothic Style

Digital Navigation

•Digital links are conventional hypermedia links, whose target is another Point of Interest or a pure digital node.

Hypermedia

Real WorldIt is located in La Plata geographical centre.

Dardo Rocha MuseumCity HallNatural Sciences Museum

La Plata Cathedral

The most outstanding building and monument in the city The magnificence of this Neo Gothic Temple which started being built in XIX Century.

Neo Gothic Style

Digital Navigation

•Even though the user navigate digitally, he is still standing in front of the same physical object.

Hypermedia

Real WorldIt is located in La Plata geographical centre.

Dardo Rocha MuseumCity HallNatural Sciences Museum

Neo Gothic Style

Neo Gothic architecture is a style of architecture, particularly associated with cathedrals and other churches, which flourished in Europe during the high and late medieval period.

Physical Navigation

•When the user selects a physical link expresses the intention to physically walk to the link’s target.

Hypermedia

Real WorldIt is located in La Plata geographical centre.

Dardo Rocha MuseumCity HallNatural Sciences Museum

Neo Gothic Style

Neo Gothic architecture is a style of architecture, particularly associated with cathedrals and other churches, which flourished in Europe during the high and late medieval period.

Physical Navigation

•The user arrives to the link’s target. At this moment the user finishes his current physical navigation.

Hypermedia

Real World

Natural Sciences Museum

It is a Neoclassic - Barroque building with ornaments typical of Pre - Columbian Cultures that place it as one of the most outstanding cultural monuments of the city.

It is located in La Plata geographical centre.

Dardo Rocha Museum

Summary

•Physical Hypermedia is just an example of a Context-Aware Mobile application.

•Other examples are:•Location based services.•Context-Aware groupware tools.•Augmented reality.•Smart homes.

•Each domain has its own complexity.

Rationale behind the discussion

•We can’t predict all possible scenarios (context information, type of sensors, kind of adaptability, etc.). Therefore we aim to:

•Provide an integration platform, that is able to accommodate different requirements.

•Define basic concepts that are common to these applications.

•Provide a set of hotspots.•Deliver frameworks that work inside the platform for the most common applications (e.g. LBS, PH, etc.).

Schema

Underlying Design and Architectural Decisions

Application Model

Aware Object

Context Features

Extending an object with its context

Application Model

Context ModelAware Object

Context Features

Extending an object with its context

Office Scheduling System

Context Model

User

Room

Projector

Location

LocationTemperature

Notebook

Noise levelActivity

Extending an object with its context

Office Scheduling System

Context Model

User

Room

Projector

Location

LocationTemperature

Notebook

Noise levelActivity

Adaptation Environments

(User) Location Based Services

Smart Room Facilities

Handling Context Changes

•Finally each environment contains a set of handlers.

•A handle is triggered each time a context feature changes.

•Example:•Smart room with different devices.•Control room temperature.•Room will have a temperature context feature.•And a handler that is triggered every time it changes.

Handling Context Changes

Office Scheduling System

Room

Projector Notebook

Keep temperature between 18 and 22

degrees Celsius

Context Model

LocationTemperature

Noise levelState Active Application

H1

Turn off the lights when the projector is showing a

presentation

Smart Room Facilities

AdaptationEnvironments

H2

Architecture mappings in PH

•In the P.H. case we might not need an underlying model.

•We start by taking into an account the user location.

Context ModelAware Object (User)

Physical Location

Architecture mappings

•This location in turn has three representations•Digital Network (i.e. Standard Hypermedia).•Physical Network (i.e. Physical Places).•Geometric Representation + City Information (i.e. City

Map).

Architecture mappings

•To add P.H. behaviour we define a suitable environment.

Context ModelAware Object (User)

Physical Location

Adaptation Environment

Physical HypermediaEnvironment

City Cartography

Architecture mappings

•We also model the digital navigation as a context feature to be able to manipulate it.

•Remember that the user can navigate digitally while standing in the same physical place.

•With these two features, we can update the browser according to the user location changes.

Architecture mappings

Context ModelAware Object (User)

Physical Location

Digital Navigation

Browser as a View of the user’s context

Architecture mappings

Context ModelAware Object (User)

Physical Location

Digital Navigation

Adaptation Environment

Physical HypermediaEnvironment

H1 H2

•Handler for updating the digital navigation when the physical location changes.

•Handler for updating the digital navigation when the user clicks on a digital url

Natural Sciences Museum

It is a Neoclassic - Barroque building with ornaments typical of Pre - Columbian Cultures that place it as one of the most outstanding cultural monuments of the city.

It is located in La Plata geographical centre.

Dardo Rocha Museum

Natural Sciences Museum

It is a Neoclassic - Barroque building with ornaments typical of Pre - Columbian Cultures that place it as one of the most outstanding cultural monuments of the city.

It is located in La Plata geographical centre.

Dardo Rocha Museum

Current Work - Physical Backtracking

•Select a specific visited physical object using physical back and next functionality.

Natural Sciences Museum

It is a Neoclassic - Barroque building with ornaments typical of Pre - Columbian Cultures that place it as one of the most outstanding cultural monuments of the city.

It is located in La Plata geographical centre.

Dardo Rocha Museum

Natural Sciences Museum

It is a Neoclassic - Barroque building with ornaments typical of Pre - Columbian Cultures that place it as one of the most outstanding cultural monuments of the city.

It is located in La Plata geographical centre.

Dardo Rocha Museum

Natural Sciences Museum

It is a Neoclassic - Barroque building with ornaments typical of Pre - Columbian Cultures that place it as one of the most outstanding cultural monuments of the city.

It is located in La Plata geographical centre.

Dardo Rocha Museum

Current Work - Physical Backtracking

•Back to a specific physical object (visited objects) should be consider a new physical navigation. The user walks to reach the selected physical object.

General Conclusions

•Our thesis is that, by discovering the set of main concepts involved in context-dependent applications, we will be able to deliver a generic platform.

•This platform is a work in progress. •As we develop new case studies, we refine the abstractions.