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Creating AlwaysBestConnected Multimedia Application for the 4:th Generation Wireless Systems

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Title: Creating AlwaysBestConnected Multimedia Application for the 4:th Generation Wireless Systems


1
Creating Always-Best-Connected Multimedia
Application for the 4th Generation Wireless
Systems
  • Johan Kristiansson
  • Department of Computer Science and Electrical
    Engineering
  • Division of Media Technology
  • Luleå university of technology
  • Licentiate presentation 2004-11-30

Supervisor/examinator Dr. Peter
Parnes Discussant Prof. Gerald Maguire Jr.
2
Agenda
  • Introduction
  • Papers
  • Application-layer Mobility support for Streaming
    Real-time Media
  • Providing Seamless Mobility with
    Competition-based Soft Handover Management
  • Market-based Bandwidth Management for Distributed
    Multimedia Applications
  • Conclusion and future work
  • Discussion

3
Introduction
  • Rapid development of wireless networks
  • UMTS/3G networks
  • WiFi networks
  • 49,263 public hotspots
  • Ad-hoc networks, e.g. MeshNetworks
  • Internet and laptop use exploding
  • 50 of all laptops have WLAN support
  • New types of applications
  • Wearable computing

Source ) http//www.jiwire.com/ (November 2004)
4
4th generation wireless system
  • There is not yet a universally agreed-upon
    definition of 4G
  • for some 3G WLAN access is already 4G
  • for some bandwidth gt 20Mb/s is already 4G
  • Diversity of wireless networks
  • WiMax, UWB etc.
  • Always-Best-Connected
  • Operator-centric view
  • User-centric view

5
Today wireless landscape
Network type n/a Capacity n/a Price n/a
Network type 802.11b Capacity 11 Mbit/s Price
Free
Network type GSM/GPRS Capacity 40.2
kbit/s Price 20 kr/Mb
Network type 802.11b Capacity 500 kbit/s Price
Free
Network type Wired Ethernet Capacity 100
Mbit/s Price Flat-rate
Network type UMTS Capacity 300 kbit/s Price 18
kr/Mb
This is a fictitious coverage map
6
Motivation
  • How to creating multimedia applications that can
    efficiently take advantage of available bandwidth
  • How to utilize bandwidth in the possible way in
    the application?
  • How to supply the application with bandwidth in
    the best possible way?
  • It should just work?!
  • How to hide heterogeneity?

7
Research problem
  • Seamless mobility (Paper 1 and 2)
  • How to allow applications switching (handover)
    between networks?
  • Why and when should a handover to another network
    be initiated?
  • To which network?
  • Adaptability (Paper 3)
  • How to adapt multimedia applications to available
    bandwidth?
  • How can bandwidth be shared between media stream?

8
Related 4G problems
  • Radio technologies
  • Power control, smart antennas etc.
  • Security aspects
  • Authentication, Authorization etc.
  • Business models
  • Billing etc.
  • Network management
  • Mobile multimedia applications

9
Research methodology
  • Exploratory research methodology
  • Marratech Pro
  • Middleware
  • Real-life experiments
  • Short time frame

10
Paper 1Application-layer Mobility support for
Streaming Real-time Media
  • Johan Kristiansson, and Peter Parnes
  • Department of Computer Science and Electrical
    Engineering
  • Division of Media Technology
  • Luleå university of technology
  • Presented at IEEE Wireless Communication and
    Networking Conference (WCNC), 2004, Georgia,
    Atlanta

11
Introduction
  • Motivation
  • Many applications cannot handle multi-homing or
    handle longer periods of time-outs.
  • Research issues
  • How to create multimedia applications that can
    rebind (handover) to a new network interface at
    any time?
  • Contribution
  • A new UDP socket abstraction (Resilient Mobile
    Socket)

12
Related work
  • Mobile IP
  • Requires support from the infrastructure
  • Limited NAT support
  • Triangular routing
  • No support for multiple interfaces
  • Mobile IPv6
  • Stream Control Transmission Protocol (SCTP)
  • Previous implementations only supported TCP
  • Limited support for mobility (ADD-IP)
  • NAT and general firewall problem (ALG is needed)
  • Operating system support is required
  • Datagram Congestion Control Protocol (DCCP)
  • Limited support for mobility
  • Few implementations

13
Resilient Mobile Socket
  • What is a socket?
  • Represents an end-point of communication link to
    other applications running on the network
  • Used by applications to send and receive packets

14
Resilient Mobile Socket
  • A new socket abstraction for UDP
  • Each internal socket represent a carrier/operator
  • Packet translation
  • Both end-point must be modified

15
Resilient Mobile Socket
  • A new socket abstraction for UDP
  • Each internal socket represent a carrier/operator
  • Packet translation
  • Both end-point must be modified

16
Demo time!! ?
17

18
Same experiment but using the RMS-enabled
prototype
19

20
Results
  • Can jitter or packet delay be used to detect a
    disconnection?

21
Discussion
  • Advantages
  • No support from the infrastructure is required
  • Support for multiple interfaces
  • Multicast support. Switch between an internal
    unicast and a multicast socket
  • No triangular routing
  • Disadvantages
  • Only UDP is supported
  • All application must be use RMS, i.e. all
    application must be modified
  • No security. Connection hijacking possible.

22
Paper 2Providing Seamless Mobility with
Competition-based Soft Handover Management
  • Johan Kristiansson, and Peter Parnes
  • Department of Computer Science and Electrical
    Engineering
  • Division of Media Technology
  • Luleå university of technology
  • Published at 7th IPIP/IEEE International
    Conference on Management of Multimedia Networks
    and Services (MMNS), California, San Diego, 2004

23
Introduction
  • Motivation
  • Real-time media require seamless mobility
  • Research issues
  • Minimize handover delay
  • Ping-pong problem
  • What is the best network for real-time media?
  • When should a handover be initialized?
  • Contribution
  • A new handover strategy for application-layer
    mobility

24
Related work
  • Architectures for minimizing the handover delay
  • Cellular IP, Hierarchical Mobile IP etc.
  • Traditional ways to trigger handovers
  • Dwell-time, hysteresis, threshold based algorithm
  • L2 information, e.g. signal-strength
  • Soft handover support
  • Must be proactive
  • Location-aided handover

25
CSHM - Problems
  • When should redundancy be enabled?
  • When should it be disabled?
  • How to deal with duplicate packets?
  • Which connection should be used after redundancy
    has been disabled?

26
CSHM - Solutions
  • When should redundancy be enabled?
  • Proactive soft handovers based on packet delay
  • Packet must be sent with a regular interval
  • Both end-points are involved in decision process
  • If packet delay gt threshold (F) then enable
    redundancy

27
CSHM - Solutions
  • When should redundancy be disabled?
  • A dwell timer (D) is used to disable redundancy
  • How to deal with duplicate packets?
  • Filtering out duplicate packets using seq. nr.
  • New performance metric packet contribution
  • Which connection should be used after redundancy
    has been disabled?
  • The one with the highest packet contribution

28
Evaluation
  • Investigate F and D relationship between packet
    delay and losses, and duplicated packets
  • Experimental setup
  • Two WiFi networks
  • Two clients sending GSM audio
  • Hard to repeat experiments
  • Emulation

29

30
Discussion
  • Advantages
  • Minimal handover delay
  • High handover frequency (Ping-pong problem)
  • Evaluate end-to-end performance
  • Minimize duplicated packets
  • Disadvantages
  • Not suitable for all media
  • Calibration of F and D is needed
  • Requires access to multiple network interfaces
  • Can make congestion worse

31
Paper 3Market-based Bandwidth Management for
Distributed Multimedia Applications
  • Johan Kristiansson, Jeremiah Scholl, and Peter
    Parnes
  • Department of Computer Science and Electrical
    Engineering
  • Division of Media Technology
  • Luleå university of technology
  • Under review

32
Introduction
  • Motivation
  • Applications must adapt to available bandwidth
  • Research issues
  • Help multimedia applications better leverage
    available bandwidth
  • Sharing/allocating bandwidth between adaptive
    media
  • Supplying application with bandwidth
  • Contribution
  • A middleware based on microeconomics for managing
    bandwidth

33
Related work
  • QoS-aware middlewares for operating system
  • Agilos
  • B. Li. Agilos A Middleware Control Architecture
    for Application-Aware Quality of Service
    Adaptations. PhD thesis, University of Illinois,
    USA, 2000.
  • Q-RAM
  • Microeconomics
  • Congestion pricing
  • CPU allocations in operating systems

34
Microeconomy
  • Microeconomy
  • Consumers and producers
  • Invisible hand
  • Equilibrium
  • Tâtonnement process
  • Spot-market

35
Calculating the supply
  • Constraints
  • Budget of the user
  • Capacity of the network(s)
  • smin(budgetUser, capacityNetwork)
  • Congestion control protocol
  • Sender-based vs receiver-based congestion control
  • TCP-Friendly Rate Control Protocol (TFRC)

36
Calculating the demand
37
Overview of the middleware
38
Evaluation
Video 25 kB/s
B
A
Audio
Video
LAN
GPRS
  • Calculating the demand
  • Calculating the supply

39
Experiment 1
Introducing a new media (audio)
Price variation
Video and audio demand variation
40
Experiment 2
Supply recalculation rate
Price recalculation rate
Price recalc. rate50ms
Supply recalc. rate800ms
Equilibrium
41
Experiment 3
Switching between a LAN network and GPRS network
Price variation
Video demand variation
42
Discussion
  • Advantages
  • Plug-and-play replacement of components
  • Equilibrium allocations are possible
  • Disadvantages
  • Using a high supply recalc. rate results less
    bandwith utilization
  • Only selling bandwidth from one network at a time

43
Final remark
  • Always-Best-Connected
  • More than just being best connected
  • Most also consider how to maximize the users net
    benefit
  • Cannot modify all applications
  • A middleware is needed!!

44
Future work
  • The second paper
  • Dynamic adjustment of F and D
  • The third paper
  • A real prototype
  • Experiments with real congestion control protocol
  • Experiments with other types market-system, e.g.
    auctioning system, or Lagrangian methods
  • Intelligent applications
  • Adapt applications (media) using contextual
    information

45
Discussion
46
Questions?
  • Contact information
  • johan.kristiansson_at_csee.ltu.se
  • http//www.sm.luth.se/johank
  • Visit this page for contact details
  • Centre of Distance-spanning Technology (CDT)
  • http//www.cdt.luth.se
  • Division of Media Technology
  • http///media.sm.luth.se
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