Delivery Context Descriptions - A Comparison and Mapping Model

Delivery Context Descrip1ons  A Comparison and Mapping Model  Chris&an Timmerer  Klagenfurt University (UNIKLU)  Faculty of Technical Sciences (TEWI)  Department of Informa&on Technology (ITEC)  Mul&media Communica&on (MMC)  h9p://research.1mmerer.com  h9p://blog.1mmerer.com  mailto:chris1an.1mmerer@itec.uni‐klu.ac.at  Co‐authors: Chris1an Timmerer, Johannes Jabornig, and Hermann Hellwagner   (UNIKLU) 

Outline  •  Introduc1on / Mo1va1on  •  Available Descrip1on Formats +  Analysis / Comparison  •  Mapping Model / Levels / Classes  •  Implementa1on  •  Conclusions  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  2 

Introduc1on  •  Access to Internet is  ubiquitous  •  Device types: sta1onary +  mobile  •  Characteris1cs manifold  •  Calls for a descrip1on of the  usage environment context  –  Diﬀerent formats available  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  3 

Mo1va1on  •  Use case: mul1media content  Terminal Devices  adapta1on  Server / Proxy /  Live Content  Access Point /Client  Mul&media Content  Adapta&on  Characteris&cs  Stored Content  Adapta&on  Capabili&es  Decision‐Taking  Condi&ons  . . .  … does not want to change/update SW each &me a  new format appears  … keep mapping eﬀort minimal  … want to have a generic approach  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  4 

Available Descrip1on Formats  RDF  Composite Capabili1es / Preference Profiles (CC/PP) – W3C  •  –  Components + a9ributes (simple|complex={bag,seq})  –  Does not define a vocabulary of terms  User Agent Profile (UAProf) – Open Mobile Alliance (OMA)  •  HW/SW Placorm: display/audio output, interac1on, media types, codecs, OS, …  –  CC/PP  BrowserUA: (X)HTML features, JavaScript, …  –  NetworkCharacteris1cs: bearer, security op1ons, Bluetooth support, …  –  Wap/PushCharacteris1cs  –  Usage Environment Descrip1on (UED) – MPEG‐21 Digital Item Adapta1on (DIA)  •  –  User characteris1cs: user informa1on, preferences, accessibility, …  XML Schema  –  Terminal capabili1es: display/audio output, codecs, power/storage, CPU, …  –  Network characteris1cs: capabili1es/condi1ons, bandwidth, error, …  –  Natural environment characteris1cs: illumina1on, noise, loca1on, 1me, …   Delivery Context Ontology (DCO) – W3C   •  OWL  Environment: loca1on, network, …   –  Hardware: display, input, memory, camera, Bluetooth, CPU, …  –  Soiware: supported APIs, data formats, OS, protocols, Java/Web browser specifics, …  –  Measure: units wrt physical electrical charges, length, unit conversion, …  –  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  5 

Analysis / Comparison  •  All standards make use of XML  –  MPEG‐21 UED: XML Schema  –  OMA UAProf: RDF (as it is based on CC/PP)  –  W3C DCO: OWL  •  Only a few but essen1al characteris1cs/capabili1es are  common across all usage environment context descrip1on  formats  –  Display capabili1es, file/coding formats, …  –  Difference in syntax, e.g., horizontal=1024, ver1cal=768 vs.  1024×768  •  CC/PP defines only a basic structure without a vocabulary  of terms   describe rela1onship between commonali1es (how? which  technology?)  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  6 

Mapping Model  •  Direct mapping model: explicit func1ons from one  standard/format to another  •  Integra1on model: common interface + func1on for  conver1ng to/from this model  •  Technology  –  XML Schema: data type and value range incompa1bili1es  cannot be described (e.g., UED: colorCapable={true,false},  UAProf: ColorCapable={Yes,No})  –  OWL: describes rela1onship between classes and proper1es  uaprof2dco  ued2dco  dco  integra1on model  dco2uaprof  dco2ued  im2ued  . . .  ued2im  ued2uaprof  ued  uaprof  dco  ued  uaprof  uaprof2ued  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  7 

Approach: Mapping Levels  •  Component: mapping of predefined group of elements/a9ributes  to similar group of the other descrip1on format  •  Elements: mapping of a9ributes/elements with equal seman1cs but  possibly different syntax, i.e., different tag names  •  Datatype: mapping of datatypes with equal domains but different  syntax   •  Value: mapping of datatypes with different domains but equal  seman1cs   Level  UAProf Example  UED Example  Component  prf:NetworkCharacteristics dia:NetworkType Element  prf:InputCharSet dia:CharacterSetCode Datatype  prf-dt:Boolean xsd:Boolean Value  Yes true 2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  8 

Examples  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  9 

Examples (cont’d)  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  10 

Mapping Classes  •  Direct: equal seman1cs and compa1ble datatypes with equal domains but  may diﬀer in their syntax (i.e., tag name)  –  E.g., dia:bitsPerPixel (xsd:integer) and prf:BitsPerPixel (prf‐dt:Number)   •  Advance: same concept (i.e., equal seman1cs) but with diﬀerent, non‐ compa1ble datatypes and/or domains  –  E.g., dia:Resolu1on (horizontal/ver1cal a9ributes) and prf:SreenSize (480x320)   •  Derive: element values can be derived from one or more elements of the  respec1ve other descrip1on format  –  E.g., prf:SoundOutputCapable derived from presence of  dia:AudioOutputCapability   •  Extend: require proprietary extensions of the respec1ve other descrip1on  format  –  E.g., UAProf WapCharacteristcs not present in UED  •  UAProf: 77 elements with direct (4), advance (7), derive (4), and extend  (62)  •  Direct (4), advance (7), and derive (4) cover most mul1media content  adapta1on scenarios  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  11 

Example  •  File/coding format: Classiﬁca1on Scheme vs. MIME  type  –  urn:mpeg:mpeg7:cs:VisualCodingFormatCS:2001:3  –  video/mp4  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  12 

Implementa1on  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  13 

Conclusions  •  Mapping of context delivery descrip1ons between different formats  •  Mapping model based on levels => four classes: direct, advance,  derive, extend  •  Defined integra1on model + formulated templates (SPARQL/OWL)  to query informa1on from this model to generate the target context  delivery format  •  Findings  –  Overlap between different formats not that huge as expected  •  Clustered around those proper1es which are considered by the majority of  applica1ons areas (e.g., screen size, coding formats, etc.)  –  Direct, advance, derive are sufficient  –  Rela1onship described manually with respect to an integra1on model   •  Requires a thorough analysis of these formats which is some1mes  cumbersome   •  Mapping func1ons need to be defined only once   –  We have demonstrated that it is feasible but requires the integra1on  of many XML‐based technologies (XML Schema, RDF, OWL, SPARQL,  XSLT, …)  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  14 

Thank you for your a9en1on  ... ques1ons, comments, etc. are welcome …   Ass.‐Prof. Dipl.‐Ing. Dr. Chris1an Timmerer  Klagenfurt University, Department of Informa1on Technology (ITEC)  Universitätsstrasse 65‐67, A‐9020 Klagenfurt, AUSTRIA  chris1an.1mmerer@itec.uni‐klu.ac.at  h9p://research.1mmerer.com/  Tel: +43/463/2700 3621 Fax: +43/463/2700 3699  © Copyright: Chris.an Timmerer  2009/03/19  Chris1an Timmerer, Klagenfurt University, Austria  15 

Delivery Context Descriptions - A Comparison and Mapping Model

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Delivery Context Descriptions - A Comparison and Mapping Model — Presentation Transcript