Delay Tolerant Streaming Services Thomas Plagemann on behalf of the DT-Stream Team

Motivation

3

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

4

5

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

6

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

7

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

6

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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