Running the Web backwards: appliance data services

'Appliance' digital devices such as handheld cameras, scanners, and microph ones generate data that people want to put on Web pages. Unfortunately nume rous complex steps are required. Contrast this with Web output: handheld We b browsers enjoy increasing infrastructural support such as user-transparen t transformation proxies, allowing unmodified Web pages to be conveniently viewed on devices not originally designed for the task. We hypothesize that the utility of input appliances will be greatly increased if they too were 'infrastructure enabled'. Appliance Data Services attempts to systematical ly describe the task domain of providing seamless and graceful interoperabi lity between input appliances and the Web. We offer an application architec ture and a validating prototype that we hope will 'open up the playing fiel d' and motivate further work. Our initial efforts have identified two main design challenges: dealing with device heterogeneity, and providing a 'no-f utz' out-of-the-box user experience for novices without sacrificing express ive power for advanced users. We address heterogeneity by isolating device and protocol heterogeneity considerations into a single extensible architec tural component, allowing most of the application logic to deal exclusively with Web-friendly protocols and formats. We address the user interface iss ue in two ways: first, by specifying how to tag input with commands that sp ecify how data are to be manipulated once injected into the infrastructure; second, by describing a late-binding mechanism for these command-tags, whi ch allows 'natural' extensions of the device's UI for application selection and minimizes the amount of configuration required before end-users benefi t from Appliance Data Services. Finally, we describe how to leverage existi ng services in the infrastructure; our prototype is based on HTTP and Java but our architecture could also leverage services connected via Jini or COR BA. We also describe an implemented prototype of parts of the architecture and a specific application. (C) 2000 Published by Elsevier Science B.V. All rights reserved.