Adaptive QoS for Service-Oriented Learning

EnvironmentsColin Allison, Martin Bateman, Ross

Nicoll and Alan Ruddle

School of Computer ScienceUniversity of St Andrews

mb@dcs.st-and.ac.uk

Overview

• Identify goals of Collaborative Learning Environments

• Educational goals -> QoS requirements

• How to meet QoS requirements• Example: Finesse – Learning

environment • Conclusions

Pedagogical Goals

• Collaboration– Synchronous

• video• audio

– Asynchronous• notebooks• instant messenger

• Ubiquitous & heterogeneous– Network– Device

• Experiential and Active Learning• Realism – ‘Live data’

Finesse

Finance Education in a Scalable Environment

• Supports teaching of fund management• Virtual portfolios at the core

– Inspect historic data– Buy/sell shares– Try to make a profit

• Notebook for asynchronous collaboration

Finesse

Pedagogical aspects of Finesse

• Asynchronous • Ubiquitous – 100% web• Realism – London Stock Exchange• Experiential

Finesse – To add

• Re-engineer to be GSDL based

• Synchronous communications– Video conferencing– Synchronous groupware

• Device independence

QoS Aspects

• User perception– Responsive– Timely– Looks good– Easy to use

• Network– Low delay– Low jitter– High bandwidth– Low packet loss

QoS Timeliness & Responsiveness

QoS Requirement

Interactive Resource Type

Example Application

Bandwidth

Sample Rate

Delay Jitter Loss Tolerant

Timelin-ess

Continuous Media

Interactive video

high 15 fps 250 ms Yes Yes

Interactive audio

Low - medium

8000 hz 250 ms Yes yes

Respon-siveness

Web-Server Based

CGI/Servlet

Low-high N/A 5 s No No

What does the Grid bring

• Common infrastructure– OGSA, WSDL, UDDI, etc

• Component sharing• Dynamic Service

Composition• QoS based service

discovery

Registry

ServiceRequester

ServiceProvider

12

3

FiGS – Finesse Grid Services

Browser

Video

User Web Servlets

GS:

Manager

GS: Notebook

GS: Conferencing

GS: Portfolio

GS: Stock Data Source 1 GS: Stock

Data Source 2Finesse

Services

Grid Services

Application

VoiceML

Video

Phone

Internet QoS Approaches

• Resource Reservation– Eg IntServ

• Aggregate flows– Eg DiffServ

• Adaptive• Best effort

– Eg most applications

IncreasingInfrastructure

Adaptive QoS Provision

• Past network conditions -> statistics– Active: RTP/RTCP traffic– Passive: Traffic monitoring

• Estimate likely network path conditions– Temporal & spatial patterns in traffic

• Inform application at start• Application adapts to changes

Location Information Server

Conference Controller Architecture for Video

Conferencing

Adaptive QoS Advantages

• Network edge deployment– Under your administrative control– Manageable traffic rates

• Learns from traffic– Sharing traffic knowledge

• Utilises session knowledge– Duration, number of participants,

type

Example Conference Configuration

Conclusions

• Collaborative Learning Environment– Achieve pedagogical goals

• Pedagogical goals -> QoS requirements

• Architecture for Adaptive QoS– Deployable now

Questions?

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