Collaborative Web Browsing Tool Supporting Audio/Video Interactive Presentations

(1)

Collaborative Web Browsing Tool

Supporting Audio/Video Interactive

Presentations

Guillermo de Jesús HOYOS-RIVERA

Roberto WILLRICH

Roberta LIMA-GOMES & Jean-Pierre COURTIAT

Department of Computer Science (INE)

LAAS-CNRS

Santa Catarina Federal University (UFSC)

Toulouse, France

Florianópolis, Brazil

{ghoyos, rgomes, courtiat}@laas.fr

[email protected]

14th IEEE International Workshops on Enabling

Technologies: Infrastructures for Collaborative Enterprises

(2)

Presentation Outline

Collaborative Web Browsing

Synchronization Model

Functional Architecture

Operational behavior of CoLab

(3)

Users are isolated when they browse the

Web

We propose to provide Web users with a

group awareness

User 1

User 2

Web Server B

(4)

The number of Web pages containing

embedded continuous media increases

quickly

New challenge for Collaborative Web

Browsing

(5)

Synchronization of

Web Browsing

Continuous media

presentations

HTTP Server

User 1 User 2 User 3

HTTP GET

RSTP Server

User 1 User 2 User 3

RSTP

PLAY!

PAUSE!

STOP!

PLAY!

PAUSE!

STOP!

PLAY!

PAUSE!

STOP!

(6)

Web browsing synchronization solutions

Communication tools

e-Mail

Windows Messenger

ICQ

Browsing indexing

CoBrow

Let’s Browse

PROOF

(7)

Web browsing synchronization solutions

Browsing synchronization

Application sharing (VNC)

E-coBrowse

WABX

PROOF

Integrated collaboration environments (NetDive,

PlaceWare, WebEx,…)

Possibility of flexibly creating/releasing

(8)

Collaborative Web Browsing

It seems that there is no currently existing

solution allowing users to synchronize

embedded continuous media presentations in

Web pages

Some problems arise, due to

Response times when clicking the “Play” button

Connection delays

Transmission delays of the RSTP packets

Transmission delays of the stream

(9)

(10)

The synchronization state of a collaborative Web

browsing session is represented in a tree

structure called SDT (Synchronization

Dependency Tree)

1

2

3

4

Asynchronous User

Synchronous Users

B

ro

w

s

in

g

A

c

ti

v

it

ie

s

P

ro

p

a

g

a

ti

o

n

D

ir

e

c

ti

o

n

(11)

Browsing synchronization in SDTs

1

2

3

4

5

Browse(URL1)

URL1

Browse(URL1)

URL2

Browse(URL2)

URL2

Browse(URL2) Browse(URL2)

1

2

3

4

5

Browse(URL1)

URL1

Browse(URL1)

URL1

URL2

URL1

(12)

Synchronization Relations are dynamically

created and released by using

Synchronization Requests, which are

subject to an authorization protocol:

“I_Follow_You”

“You_Follow_Me”

(13)

The “I_Follow_You” request:

Can I see what

you are reading?

Of course!

A

B

A

SDT

(14)

The “I_Leave_You” request:

A

B

A

I quit you,

See you!

SDT

I_Leave_You

(15)

The “You_Follow_Me” request:

A

B

A

Do you want to see

this information?

OK, I’m

coming!

SDT

I_Accept

You_Follow_Me

(16)

Continuous media presentations

synchronization is made according to the

synchronization relations among users: the

user at the root of a SDT has the control

(17)

(18)

Client

Users

Role

Login/out &

Synchronization

Actions

Browsing

Actions

Session

Information

Exchange

Resource

Retrieval

Internet/Intranet

Broker

Integration API

Session Manager

External Tools

Browsing

Requests

Browser

Plug-in

Media

Controller

Media

Controller

Browsing

Controller

Browsing

Controller

Playback control &

State Changes

Playback Control &

State Changes

Media

Streaming

MediaSync

Manager

MediaSync

Manager

Browsing

Manager

Browsing

Manager

Session

Information

Exchange

Session Managing

and integration

Browsing request

treating

Resource

retrieval

PrepareToPlay

Play, Stop & Pause

Integration with the

server and synchronization

requests treating

Capture state changes

and execute Playback

(19)

Collaborative Browsing

(20)

Current Implementation

Browsing Manager

Translator

Cache

Module

Cache

Module

Cache

T

ran

s.

re

q

. 7

T

ran

s.

re

sp

. 8

Tr

an

s.

res

p.

8

Caching

9

Cach

4

ed?

Get

cach

ed

18

Ge

t

cac

hed

17

Internet/Intranet

6

H

T

P

re

q

u

es

t

5

H

T

P

re

sp

on

se

MediaSync

Manager

MediaSync

Manager

Retriever

Control

Data

Broker

H

T

P

re

q

.

1

H

T

P

re

sp

.

11

10

12

Synchronize?

13

∀

∀Slave ⇒

⇒

URL

H

T

P

re

q

.

14

H

T

P

r

es

p

.

20

H

T

P

r

eq

.

3

H

T

P

re

sp

.

Can access?

2

Session

Manager

Session

Manager

Synchronization

Module

Synchronization

Module

23

State Change

24

Asynchronous User

Playback Control

22

State Change

Playback Control

Synchronous User

21

15

16

19

(21)

Current Implementation

Media synchronization mechanism

The “PrepareToPlay” command allows us to control

the synchronization of the state of the whole

presentation in spite of the non deterministic

connection and buffering times

MediaSync Manager

Client A

Client B

Client C

Connecting

PrepareToPlay

ReadyToPlay

(22)

(23)

Current Implementation

G

U

I

B

row

si

ng

F

ra

m

e

(24)

Current Implementation

Browsing Controls

User’s Identity and

Session Name

Awareness &

Synchronization State

Synchronization Controls

(for Users and Roles)

(25)

(26)

Current Implementation

1 ≤ N ≤ 165

0

200

400

600

800

1000

1200

1400

T

i

m

e

(

m

s

)

1

15

30

45

60

75

90

105

120

135

150

165

Number of Users

(27)

Collaborative Browsing

(28)

Conclusions

Allowing flexible synchronization relations

creation/release is a good issue

Usable on any standard browser following the

W3C standard specification and supporting the

automatic proxy configuration and on any HTML

resource

Continuous media presentations

synchronization: a new issue particularly useful

in e-learning

Flexible extensible architecture

(29)

Future Work

Implementation of a distributed version

API’s development for integrating our

platform with other collaborative tools

Implementing enhanced synchronization

mode using roles privileges:

(30)