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VERDIKT conference 2012
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Delay Tolerant Streaming Services Thomas Plagemann on behalf of the DT-Stream Team
Motivation
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Mobile Ad-Hoc Network
Using head mounted camera Streaming live video
Motivation (cont.)
• Communication to CCC using head mounted cameras
• Networking infrastructure might not be available è use mobile phones to establish wireless ad-hoc network
• Problem: mobile, unstable, partitioned network • Opportunity: video can also be useful when it arrives
late
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This is a mock-up
Motivation (cont.)
History and Funding
• Pre-project in 2008 at UiO – 4 Master students – Collaboration with University of Oviedo (Spain)
• Verdikt funding: 3 PhDs & 1 PostDoc (2008 – 2012)
• University of Oviedo funding: 1 PhD
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Technical Challenges
• Mobile wireless space – how to be always best connected?
• Mobile phones have resource restrictions and therefore the network they create – Network topology awareness – Cross-layer optimization – Simulation tools not appropriate
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The Mobile Wireless Space
8 Node Density
“ Relat
ive M
obility
”
High
Low
High
Space Paths
Low
No (Space/Time) Paths
Space/Time Paths
Hybrid Environments
The Overall Approach
• Adaptive Overlay for Delay Tolerant Streaming
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DT-S DT-S DT-S
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5
4
7
1
3
2
DT-S overlay
Mobile Ad-hoc Network
A few Results Highlighted
• Early results used to focus the research: – Survey of video streaming over MANETs – Real world experiments
• Recent results: – Modeling mobile nodes in network simulators – Systematic cross-layer optimization – At home in heterogeneous networks – Non-intrusive network clustering
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Video Streaming over MANETs
• M. Lindeberg, S. Kristiansen, T. Plagemann, V. Goebel: “Challenges and techniques for video streaming over mobile ad hoc networks”, Multimedia Systems Journal, 2010
– Over 100 papers analyzed
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Real World Experiments • Kristiansen, S., Lindeberg, M., Rodríguez-Fernández, D.,
Plagemann, T.: “On the Forwarding Capability of Mobile Handhelds for Video Streaming over MANETs”, ACM MobiHeld 2010 at ACM SIGCOMM 2010, August 2010
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M S R
F
Sender 2.6 GHz Intel Centrino Duo Core 3 GB RAM
Receiver 2.6 GHz Intel Centrino Duo core 3 GB RAM
Forwarder Nokia N900
Monitor 2.2 GHz Intel Centrino Duo Core 2 GB RAM
Bomb shelter
Take away points: Mobile phones are a bottleneck Introduce non-neglect able delay Severe at saturation point
Real World vs. Simulation
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Nokia N900
Towards realistic simulation
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Network Simulator Execution Model
Shared resources
Scheduler Simulator
Progress Processing Stages
Obtain Execution Time Distribution from SEM and Resource Utilization State
Schedule Payload in Scheduler Simulator
Update
Update
Traffic
Request Execution
Execute Threads
Program Model
+
SrvB SrvA
SEMA
…
Service Mapping
SEMB SEMC
Traffic Generation and Tracing
1. Extract protocol models from existing devices 2. Map onto protocols in existing network simulators 3. Synchronize execution with threads in a scheduler
simulator
1
2
3
Initial Results
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0
0.5
1
1.5
2
0 200 400 600 800 1000 1200 1400
Intr
a-N
ode
Del
ay (m
s)
Packet Size (Bytes)
Model Accuracy (10 pps, ICMP Echo)
Real World
Vanilla Ns-3Node Model
Cross-layer Adaptation • Lindeberg, M., Kristiansen, S., Goebel, V., Plagemann, T.: “MAC Layer
Support for Delay Tolerant Video Transport in Disruptive MANETs”, IFIP Networking 2011, Valencia, Spain, May 2011
• MAC Support w/Cross-layer Interaction • Check ARP if IP address is known (ARP Adapt) • Check MAC transmission queue: if filling, link is down, stop using it
(Link Adapt) • Return packets from MAC layer instead of dropping (MAC Return) • We can reduce retransmission limit, and avoid most packet
losses!
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CCCCCCCr2Cr1
I5I4
Cr1
I5I4
I3I3
I2
I
I1
I2
I1Sr
Ix - Intermediate node(s)Sr - Source node
Crx- Carrier node(s)CCC - Command Control Center
Location of the accident
500 m
500
m
Command and control center
Distance=1750 m
Dts-Overlay
UDP
IP / OLSR
MAC(IEEE 802.11 a/b)
Route availability
+MAC address/ARP status
Rejectedpackets
+Retransmission
queue status
PHY(IEEE 802.11 a/b)
Dts-Overlay
UDP
IP / OLSR
MAC(IEEE 802.11 a/b)
PHY(IEEE 802.11 a/b)
<OverlayMessage>
Node 1 Node 2
Cross-layer Adaptation (cont.)
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Standardized, convenient, and efficient access to information
No “hard-wiring” to particular protocol implementations
Using complex events
Multihoming in Heterogenous Network Paradigms • D. Rodriguez-Fernandez, I. Martinez-Yelmo, E. Munthe-Kaas, T. Plagemann:
“Always Best (Dis-)Connected: Challenges to Interconnect Highly Heterogeneous Networks”, Special Issue of the Journal of Internet Engineering on Future Network Architectures, 2012
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Community
MANET
DTN
MANET 3G
Real World
MANET Internet DTN MANET
Internet
Multihoming in Heterogenous Network Paradigms (cont.)
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Community Framework Community Overlays
Applications
NSAL Underlays
IP DTN IP (MANET)
Mon
itorin
g Fr
amew
ork
3G 802.11
Cro
ss-la
yerin
g In
form
atio
n Fr
amew
ork
Internet NSAL
MANET NSAL
DTN NSAL
Application
Community B Community A
Networking Substrata
Community Support Layer (CSL)
…
…
NSAL API
…
…
Community Socket API
Community Socket
Non-intrusive Clustering of MANETS • Drugan, O., Munthe-Kaas, E., Plagemann, T.: “Detecting Communities
in Sparse MANETs”, IEEE/ACM Transactions on Networking, 2011
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Topology from OLSR routing table….. …. and with exact position… … and 100m range
Where are we now?
• All PhD students scheduled to submit their thesis in 2012
• A good set of papers is published but several are in the queue
• Most results are useful far beyond DT-Stream (cf. highlights)
• Many of the core pieces are implemented for an integrated demo prototype (also with numerous MSc Theses)
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Where do we go …
• Look for funding to move basic research results of DT-Stream to applied research results, i.e., integrated demo prototype ++
• Head for further long term challenges … next slides
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Future Technological Developments
• Bigger, faster, higher resolution, more media, more Ds – Data centers, scientific computing, home entertainment
• Smaller, everywhere, new range of I/O devices, energy concerns – Smart phones, sensors, actuators
• Ever increasing heterogeneity in computing and networking
• è diversity, separation, and seamless integration 23
Rethink Fundamentals
• “there is a need to deeply rethink the modelling and architecting of future pervasive systems” M. Conti et al., CNR
• “to fully realize the potential of CPS, the core abstractions of computing need to be rethought” A. Lee, Stanford University
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Rethink Fundamentals of the Future Internet
25 Hotel Internet
Assume the hotel gets old…. … where will stakeholders invest
…upper floors renovations brings “immediate” turn on investment
…but what if the foundations are rotten?
…have we invested enough in the fundamentals of the Internet, IP, DNS, BGP?
Technological Challenges
• From cross-layer optimization to new foundations for engineering computer/network systems? – Layers simplify design and
engineering – Layers simplify testing – Layers are in conflict with
context aware solutions
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Technological Challenges
• Smart phones and wireless sensors and actuators: – Promise to solve many challenges society faces,
e.g., sustainable environment etc., demographic change ++
– Sharing enables many new solutions, e.g., pervasive sensing vs. privacy and ownership
– From application specific solutions to foundations that span several/all application domains?
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Non-technical (non-trivial) Challenge
• Acquire funding
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Questions?
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