Managing Bandwidth in Multimedia Applications using a Marketbased Middleware

1
Managing Bandwidth in Multimedia Applications
using a Market-based Middleware

• Johan Kristiansson, Jeremiah Scholl, and Peter
  Parnes
• Department of Computer Science Electrical
  Engineering
• Luleå University of Technology, Sweden
• MMNS2005 051025

2
Agenda

• Introduction
• Related work
• Market-based bandwidth management
• Overview of the middleware
• Evaluation
• Discussion
• Questions

3
Introduction

• Distributed multimedia applications
• Bandwidth requirements can rapidly change
• Wireless landscape
• Available bandwidth can rapidly change
• How can bandwidth be shared efficiently between
  the different media inside a multimedia
  application in order to provide the user with the
  optimal aggregate experience?
• Interdisciplinary knowledge is required
• Networking specialist
• Usability specialist

4
What is this paper all about?

• Middleware framework based microeconomic
  principles
• Supply and demand
• Management system in the application-layer
• Various solutions related to network management
  (usually affecting the supply) and the various
  solutions related to usability (usually affecting
  demand) to be researched and integrated
  separately into an application.

5
Related work

• QoS support in distributed system
• Agile QoS, Q-RAM etc.
• Priced-based Congestion-control
• Market Managed Multi-Service Internet (M3I)
• Deployment issues
• User may find dynamic pricing unacceptable

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Market-based bandwidth management

• The idea Use microeconomic theory in a virtual
  market inside an application in order to make it
  easy to combine various network services while
  maintaining the efficient use of resources.
• Bandwidth is traded by consumers and suppliers.
• Equilibrium is reached when demand for bandwidth
  at the going price equals the supply for
  bandwidth at that price.

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The virtual market
Audio
Video
Other
Chat
Broker
WLAN/LTU
UMTS/GPRS
GSM/GPRS
Other
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Tâtonnement process

• A tâtonnement process is used to adjust the price
  iteratively until an equilibrium price is
  obtained.
• p p
• Over-demand and under-demand

d
s
n1
n
9
Overview of the middleware
Multimedia application
Adapt utility function
Adapt bandwidth usage
Bandwidth Consumer Agent
Bandwidth Broker Agent
Packets
Buy/request bandwidth
Receipt
Bandwidth Broker Agent
Information about demand
Information about supply
Configure
IP Mobility protocol
Network agent
Information About available networks
Configure
Operating system
10
Calculating the supply

• Bottleneck bandwidth
• Budget controls
• Measuring bandwidth
• Pathchar, Packet-Pair algorithm, congestion
  control algorithms
• Separate markets for separate end-points or
  multicast groups

11
Calculating the demand
Utility

• Demand is calculated by creating a utility
  function for each media that maps the gain with
  different bandwidth levels.
• The Bandwidth Consumer Agent calculates the
  consumer surplus (CS) in order to calculate the
  amount of bandwidth to purchase.
• u (x ) p

Utility function, u(x)

Price function, p(x)
CS
Bandwidth
CS
X
CS
m
12
Evaluation

• Proof of concept prototype
• Marratech Pro
• Audio, Video, chat, WB, Web, remote desktop
  sharing
• Packet distribution
• IP multicast or an E-meeting Portal (unicast)

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Experiment setup
Client A
Client B
Marratech Manager

• Two Marratech Pro clients
• Client A used the prototype.
• Client B was only used to change level of
  incoming to traffic
• Supply
• S s - bw , s 100
  kB/s
• Utility functions
• Audio u (x) 0 xltx or
  infinity xgtx
• Video u (x) ln(1 x) gt x (p)
  -1

limit
received
limit
min
min
audio
audio
audio
1
video
video
p
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Bandwidth sharing between multiple media

• Video back off to make room for audio

Audio demand
Video demand
The price goes up
15
Investigation into recalculation rates

• Higher price recalculation rate leads to more
  efficient allocation of bandwidth

• Higher supply recalculation rate causes
  instability.

16
Utilizing multiple networks

• Test how the system handles large variation in
  supply.
• Resilient Mobile Socket was used to add mobility
  support.

Handover to a GPRS network
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Discussion

• View bandwidth as a universal commodity
• Use virtual price/market to share bandwidth
• Each component can contribute to the equilibrium
  separately
• Networking specialist can develop better methods
  to obtain bandwidth (NA).
• Usability specialist can develop new method to
  utilize bandwidth by defining utility functions
  (BCA).

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Discussion

• Possible to allocate bandwidth close to an
  equilibrium allocation by using a high price
  recalculation rate and a low supply recalculation
• Future work
• Use a real congestion control algorithm
• More effective utility functions
• More sophisticated experiments.

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Questions?

• Contact information
• johan.kristiansson_at_csee.ltu.se
• http//www.csee.ltu.se/johank
• Visit this page for contact details
• The media technology research group
• http//media.csee.ltu.se