Websplitter: Multi-Device Collaborative Web Browsing

This paper presents an architecture and a corresponding design that
enables multiple devices, e.g. laptop, wireless PDA, projection
display, stereo speakers, to collaborate in a joint presentation of a
Web browsing session. WebSplitter enriches the Web browsing
experience of a resource-limited mobile device, such as a wireless
PDA, by enabling the mobile device to exploit the multimedia
capabilities of other devices in the vicinity, and thereby overcome
its own limitations. WebSplitter first splits a requested Web page
into different sub-documents and/or media components and then sends
these sub-documents/components to a variety of local devices. The
collection of devices, ranging from fixed entities such as a large
projection display or a stereo system to mobile entities such as a PDA
or a Bluetooth-enabled personal area network (PAN), are coordinated
via WebSplitter to dynamically create an enhanced composite Web
presentation. Among the applications enabled by WebSplitter is that
of a wireless PDA acting as a remote control for a browsing session
presented over a room's projection screen and stereo system. Since
devices may be owned by different human users, WebSplitter extends its
design to integrate the concept of joint multi-user presentation,
i.e. collaborative groupware or conferencing, with the notion of
multi-device presentation of a Web document. The WebSplitter
architecture consists of three components: an XML metadata policy file
that defines rules governing which tags in an XML Web page can be
received by which groups of users in a browsing session; a middleware
proxy that splits Web content based on the identity of a user, the
capabilities of that user's output devices, and the access control
privileges granted in the policy file to that user's group; and a
client-side component, e.g. applet or other technology, for user login
and reception of pushed browsing data. Our architecture incorporates
themes from service discovery and user management in order to discover
and register proxies, Web browsing sessions, as well as each device's
characteristics, e.g. address, capabilities, owner. We describe a
preliminary implementation of WebSplitter in which we demonstrate the
feasibility of splitting the different tags in an XML Web page to
different end users' browsers. We also demonstrate the feasibility of
pushing updates from the browsing session, e.g. new Web pages, to
heterogeneous devices, including a laptop and a PDA.

Keywords: multiple devices, collaboration, mobile, PDA, proxy,
groupware, remote control, XML, PAN, service discovery, middleware,
access control