Currentdevelopments in embeddedsystems in domainssuch as home appliances, sensor net, or simple everydayobjectbeingtaggedwith RFID:Show thatthey are gettingincreasinglysmarter and connectedwhichlead to a very large ecosystem of smart thingsLet us think of an electronic article surveillance system in a store thatwouldleveragethiseco-system: tag objectswith RFID trigger the RFID readerswith a proximitysensor trigger the security camera if somethingwasstolenbroadcast the information to the staff on their mobile phones
This leads to a problemresearched by many, showing:ToomuchprotocolsheterogeneityExpensive and time-consumingexpertknowledgeRequirements for application layer for the IoT
Four layers but: Not OSI:layers are flexible, eacheases a little more building applications: from Embedded Syst. Dev to End-UsersContribution: LayersBuilding blocks: each block is a Web APIApplications testingthese blocks
Resource Tree:functionality of the sun spot identified by resolvableURIsNot bound to one representation. We use HTML for browsability, JSON for mashups, HTTP has a content-negotiationmechanism for selecting the right representation.GET on temperature => retrieves the representation of the tempsensorPUT on LED => changes the state of the LED (on/off)
One of ourcore contributionsFor smart thingsthat do not speak Internet or Web protocolswe propose a lightweight software frameworkthatcanbedeployed on computers at the edge of the network (e.g., NAS, wifi routers, etc.):Device Drivers: encapsulate the proprietary or low-levelprotocolsCore Services: are used by drivers to maptheirfunctionality to a Web APIPluggable Services: services implementing cross-cuttingconcerns (seenextlayers)Maybeaddstuff about Web Sockets
Withthis layer wewant to achievetwothings:MakethingsfindableusingsearchenginesAllow the semi-automaticintegrationintomashuptoolsGuinard, D., Trifa, V., Mattern, F., & Wilde, E. (2011). From the Internet of Things to the Web of Things: Resource-oriented Architecture and Best Practices. In D. Uckelmann, M. Harrison, & F. Michahelles (Eds.), Architecting the Internet of Things (pp. 97-129). Berlin, Heidelberg: Springer Berlin Heidelberg. Retrieved from http://www.springerlink.com/content/p314x13322qnw276
SAC: Manages Access to Smart ThingsThrough Social NetworksAnd offers an API for clients or client applicationsRequirements (details):Security: prevent attackers from gaining accessEase of use: significantly influences adoption [Ion2010]Reflecting existing trust modelsInteroperable: Web protocols, prevent user lock-inIntegrated Advertisement
Smart things are securedbased on HTTP Basic AccessAuthentication or HTTP DigestAuthenticationAuthenticationthroughOauthUsing the social network API (OpenSocial if supported, otherwise social network proprietary API)
List of resources (i.e., services) thatcanbesharedisautomaticallygenerated by crawling (see sharing layer)
Manualmashupdev:Wetake a device on whichappscanbedeveloped by domainspecialists and, using the otherlayers, bringit to Web developers
ClickScript [Naef2009]: Language created to teach programming to children.Client-side Web technologies (JavaScript + CSS + HTML).Smart Things building-block within a few lines of JavaScript.Added push support (tPusher).
We use the RFID network in place (e.g. SAP AII)We bring this network to the Web (REST)Every tagged object in the world gets a URL!The big community of Web developers can develop Widgets for the RFID network.
Bringingdevelopment as close as possible to endusersWecreated a frameworkthatallows the creation of dedicatedmashup editorsi.e., Web toolthat let usersbuildmashupssimply by visuallycomposingwidgetsThanks to the otherlayerseachwidgetisreduced to an HTTP call and canevenbeautomaticallygenerated.This is the EAS mashup.
Web of Things architecture:Blueprints to bring IoT application development closer to non-specialists thanks to the Web:Performances are acceptable for sub-second use-casesUnveils integration possibilities (browser integration, social networks, Web scripting languages, mashups, etc.)Fosters open, participatory innovation to physicalmashupsEvaluated and prototyped in two domains:Wireless Sensor Networks & RFIDDeliverables: ~20 co-authored publications, 5 frameworks (3 open-source), 10 applications (1 open-source)