Lyngby, May 2007Diego R. Lopez, RedIRISFrancisco Cruz, UC3MCatalin Meirosu, TERENA

JRES2005, Marseille

ARCAFederated Access to Multimedia Content

TNC. Lyngby, May 2007

Extending media services

• Requirements are growing beyond the live netcasting and/or streaming availability

• Authors want content accessed• Consumers want content accessible• The obvious response is the access portal

The broader the better

• Simple to use Plug-and-play Plug-and-be-played

TNC. Lyngby, May 2007

The fate of common directories

• Common directories are the usual answer to the problem of resource location in broad communities But they face data partition Formats, protocols, security (and privacy) considerations

• Participation requires a high effort Staff and/or technological And related to local visibility

The result is the continuous re-building of central repositories of data Almost automatically outdated with respect to their once local

sources Momentum decreases with time

TNC. Lyngby, May 2007

Federating is divine

• The federated model comes into play once again• Accessing or collecting using a trusted links

And a common language for data exchange

• Maintaining total autonomy for the federated repository Policies Methods Interfaces Local visibility

• Offering a common view of information That can be enhanced for particular communities

TNC. Lyngby, May 2007

ARCA

• “Ark” in Spanish• Agregador RSS para la Comunidad Académica

(RSS Aggregator for the Academic Community) http://arca.uc3m.es/ http://www.rediris.es/pruebas/arca/

• Main goals Harmonize and centralize all the information about available

multimedia content. Up-to-date information

• Specially, with respect to changes in each institution schedules Flexibility for participating institutions, so they can change

announcements on their own• And keep their own announcement systems

• In use by the RedIRIS community• Being currently evaluated by TERENA

TNC. Lyngby, May 2007

The architecture

• The system is divided into channels. A channel represents a source of multimedia content

• Every institution is associated with one or more channels

• Each channel contains a series of events, retransmissions and/or multimedia contents, called “channel items”

• Each institution must generate data about its own channel, as well as data for all the items to be transmitted through the channel By means of RSS elements

TNC. Lyngby, May 2007

On RSS

• ARCA uses RSS 2.0 as exchange format XML as markup The more widespread format for content syndication and re-

diffusion

• It allows for collecting data using off-the-shelf software (RSS aggregators)

• Validation is simple, so it is possible to guarantee that each participant is making a correct data export

• Each participant can include additional information to its RSS description without affecting system behavior

• It allows for simple extension of system functionality

TNC. Lyngby, May 2007

RSS formats

• A general RSS format has been defined, with specific labels for each content type (direct, VoD, podcast)

• UTF-8 is required• No single RSS fulfills system requirements, so three

different namespaces are in use: Yahoo media RSS: Data about multimedia content Itunes RSS: Data about multimedia content and podcasting Google base events RSS: Announcements of programmed

events

• New namespaces can be included as the system requirements evolve

TNC. Lyngby, May 2007

The ARCA database

• RSS descriptions are collected at well-defined endpoints

• The ARCA aggregator periodically connects and retrieves them

• The system consolidates into a single database all the information collected from the participating sources

• Through this database, information about channels and items can be accessed by means of the different ARCA search and browsing facilities

TNC. Lyngby, May 2007

Topology

ARCA Server

Internet

RSS Cataloging/ Production Systems

Updated every N hours

Client.RSS Reader

for PDA/PPC

Client.RSS

Reader

Client.ARCAPortal

University

ResearchCenter

University

University

ResearchCenter

University

Multimedia

Servers

TNC. Lyngby, May 2007

The ARCA portal

• Supports different search/browsing paradigms Lists of events Calendar Queries on metadata Browsing different classifications

• Searches can be constrained according to institution, type of content, categories in a classification,...

• Multilingual support Currently: Castilian, Catalan and English

TNC. Lyngby, May 2007

The ARCA portal -II

• Offers live RSS creation for queries It is possible to subscribe to specific feeds

• Playing of all items either embedded or via external viewers

• Supports direct playing of podcasts The portal can act as an “universal podcast player”

• iTunes friendly The RSS for podcasts can be directly fed into

• Admin interface Manage data sources Manage categories

TNC. Lyngby, May 2007

Some facts and figures

• Based on open Apache, PHP5 and MySQL• Seven institutions currently participating

Plus the biggest Spanish virtual university (UNED) that committed to join along June

• ~700 items available• Two classifications in operation

Spanish Higher Education directives UNESCO codes

• Other components available Statistics (URJC) Joomla agent (UPM) Item builder (UNICAN)

TNC. Lyngby, May 2007

And more to come

• Dynamic endpoint definition• Ad-hoc creation for items dealing with sparse

live events at the portal• Enhanced admin interface, including detailed

statistics • Support for groups of events (courses,

workshops,...) when searching/browsing• Display of related items• Support for OMPL and (possibly) ATOM 1.0

TNC. Lyngby, May 2007

The long awaited demo