The LUCeS Conferencing Tool

Enhancing the Collaboration Experience

Adrian Fish a.fish@lancaster.ac.ukMiguel Gonzalez m.gonzalez@lancaster.ac.uk

LUCeS (Lancaster University Centre for e-Science)

Table of Contents

• Background• The Conferencing Tool and Some Use

Cases• Work in Progress• Technical Stuff

Background

Sakai(In a nutshell …)

• Sakai is open source software designed primarily to provide online learning environments for universities and colleges

• It provides lots of default functionality, like group resource sharing, textual chat, discussion boards, course authoring and assessment tools.

• It is an application framework in that it provides services to programmers who want to add new functionality. The units of functionality in the case of Sakai are called tools

The VRE Demonstrator Project (in a nutshell …)

• The project will provide a suite of useful tools hosted in a Sakai ‘portal’. It will give tangible demonstrations of the benefit of such tools for distributed scientific teams.

• Users of the demonstrator will get all of Sakai’s collaboration tools plus our conferencing tool and happiness prevails! In theory of course …

• The VRE Demonstrator project is funded by the JISC. The project is a collaborative effort between 4 UK institutions, Lancaster, CCLRC Daresbury, Oxford and Portsmouth

The Tool and Some Use Cases

Overview

• Delivered as a Java applet, via a web browser

• Offers powerful functionality such as video conferencing, shared desktop, whiteboard, etc from one simple user interface

• Completely free and open source• Does not require exotic (expensive)

hardware to run successfully

Conferencing Tool Components

• Conferencing – Create and participate in audio and video conferences

• Whiteboard – A many-to-many drawing tool• Shared Desktop – A one-to-many desktop

sharing tool• Chat – A basic group chat• MovieCaster – Broadcast a .mpeg,.mov

or .avi movie from your PC to the others in the conference

The Tool Interface

Whiteboard

• The whiteboard allows a group of worksite users to collaboratively draw and manipulate shapes on a canvas

• All participants receive the shapes from every other participant

• Can be used with the video tool to build freehand diagrams as a team, work on mathematical formulae, etc.

• Drops straight into Sakai with minimal configuration

• Uses the ConferencingService (more about that later) to route the shape modifications to whiteboard participants

Whiteboard

Shared Desktop

• Allows Sakai users to broadcast JPEG images of their desktop to a select group of fellow worksite users

• Network friendly. Only the area of screen that has changed is sent to subscribers

• When used in conjunction with the audio tool you have a powerful tool for document editing or collaborative software development

• Only the producer needs to have installed the software visible in the display being broadcast -all that is being sent is a stream of JPEGs

Shared Desktop Use Cases

• A team wants to work on a document together. As one types the others watch, and can discuss the changes using the audio tool. This could be a Word document, a Java source file in Eclipse, Photoshop …

• A tutor demonstrates some software to her students. She uses the software whilst talking about her actions. The students watch, listen and can ask questions via the audio tool

Starting the Producer

Shared Desktop Player

Conferencing

• Gives Sakai worksite users the ability to start, and participate in, full multi-way audio and video conferences from within the Sakai environment

• The audio tool adds value to the other tools in the suite - it is hard ‘doing’ textual chat whilst using a whiteboard!

Conferencing

Conferencing

Work in Progress

Whiteboard WiP

• Broadcast mode: One participant is designated the broadcaster, the rest are viewers. This will satisfy the well known scenario of a teacher in a classroom.

• Saving Drawings: Each participant will be able to save the drawing, in its current state, to the Sakai resources tool. In broadcast mode only the broadcaster will be able to do this

Conferencing WiP

• Floor Control: Both turn based or moderator controlled floor control

• AG Integration: A protocol bridge to VIC/RAT to allow AGN session participants to join Sakai hosted sessions

Shared Desktop WiP

• Document Handoff: Participants can take turns editing (and broadcasting) a document by passing the document file between themselves

• Whiteboard Integration: This will allow operations such as taking a still of the desktop into a whiteboard session for annotation purposes

Conference Recording

• We are currently working on a mechanism for recording the entire conference.

• The messages from every component are recorded, the video, whiteboard, shared desktop and chat.

• When you playback a conference everything occurs in the same sequence as during the live conference

Encryption

• We are currently working on a mechanism for the generation and distribution of a synchronous key for conference encryption

• Each conferencing tool instance requests the conference key over a SSL encrypted link, then uses that key to encrypt any further network traffic.

Technical Stuff

MessagingService

• A Spring component that allows tool clients to create new channels with specified users

• Drops into Sakai using a standard maven build• Is currently used by the whiteboard and

shared desktop tools, but is generic enough to be easily used for others

• Comes with a Sakai tool base class that handles all of the interaction with the messaging service. This can be specialised into your tool by implementing a few simple methods

Shared Desktop

• Uses the ConferencingService to send JPEG desktop snapshots to channel subscribers

• Screen is broken into a set of tiles, designed to fit into a 64KB datagram packet. At 32bpp colour depth, this equates to a 128 pixel square tile per datagram

• Only the tiles that have changed are sent; this should hopefully reduce bandwidth requirements

• One-to-many. The user that creates the channel becomes the publisher and their screen is grabbed, split and broadcast to the other channel users.

Whiteboard

• Shape modifications are encoded inside UDP packets

• The packet is sent to the conferencing service, which then sends it on to all the channel subscribers

• Subscribers extract the modification instruction and duplicate it on their whiteboard instance

ConferencingService

• The conferencing service is a Spring component that drops into Sakai and needs minimal configuration

• It sets up four datagram sockets and routes RTP packets received on these sockets to the relevant conference object

• Implements a software multicast algorithm and delivers all the received datagrams to all conference subscribers

• Has message distribution capabilities for lower throughput applications like the whiteboard and chat components

Conferencing Service

Sakai

The InternetThe Internet

Dispatcher Conference

Audio/Video Conferencing

• Both audio and video conferences are controlled from one Sakai tool

• Both use JMF on the client and the conferencing service on the server (Sakai)

• The conferencing service is a software multicasting system and follows the well known publish/subscribe model for users joining conferences

• It needs four ports open on the Sakai host machine, two for audio’s data and control (RTP and RTCP) packets and two for the video. The service dispatches the packets to the correct conference object for forwarding to subscribers

About the Developers

• We work for the Centre for e-Science (LUCeS) at Lancaster University in the UK

• We are currently funded, under the Sakai VRE Demonstrator project and have been focusing on developing advanced collaboration tools that extend and complement the standard ‘out of the box’ tool set that comes with Sakai

The LUCeS Conferencing Tool

Enhancing the Collaboration Experience

Adrian Fish a.fish@lancaster.ac.ukMiguel Gonzalez m.gonzalez@lancaster.ac.uk

LUCeS (Lancaster University Centre for e-Science)