DTN technology as enabler of cost-efficient networking with wired and wireless integration

- DTNRG in IETF76 -

Masato Tsuru *1,*2

tsuru@cse.kyutech.ac.jpShinya Yamamura *2, Akira Nagata *2

{yamamura, nagata}@nict.go.jp*1: Network Design Research Center, Kyushu Institute of Technology (JAPAN)

*2: Service Platform Architecture Research Center, National Institute of Information and Communications Technology (JAPAN)

2

DTN-related Project Structure in NICT

NICT: National Inst. of Information & Comm. Technology An incorporated administrative agency for R&D on Information Comm.

Technologies supported by MIC (Ministry of Internal Affairs and Comm.) as the competent authority (http://nict.go.jp/index.html)

1. Virtually Sustainable Access Networking Project (2006-2008) Fundamental techniques: Epidemic routing, Network coding, Wifi rerouting, Multi-

path transport, etc. Collaborated by Kyushu Inst. Tech., Osaka Univ. and Kwansei Gakuin Univ.

T. Matsuda, T. Takine: (p,q)-epidemic routing for sparsely populated mobile ad hoc networks, IEEE J-SAC 26(5):783-793.

T. Matsuda, T. Noguchi, T. Takine: Broadcasting with Randomized Network Coding in Dense Wireless Ad Hoc Networks, IEICE Trans. Comm. E91-B(10):3216-3225

2. Integrated Wired and Wireless Network Platform Project (2009-2010) Under JGN2plus R&D on Platform Technologies for the New Generation Network

by NICT Service Platform Architecture Research Center More architectural R&D towards Future Internet services

Copyright © 2009 National Institute of Information and Communications Technology (NICT) All Rights Reserved.

promotion

3

Low-earth orbit satellite

The Internet

Ｃｅｌｌｐｈｏｎｅ

Aircraft

Sensor Network

Vehicle

Mars

Battlefield

Communication outsideof the Internet

DTN: Delay and Disruption Tolerant Networking

Copyright © 2009 National Institute of Information and Communications Technology (NICT) All Rights Reserved.

DTN technology is designed to overcome limitations in connectivity or performance due to Opportunistic or scheduled intermittent links, Huge error rate links (packet losses), Huge or highly variable delay links, Link bandwidth/loss/delay asymmetry, Internetworking among heterogeneous network architectures, .. etc

Originally targeting challenged environments such as Inter-Planetary Internet But later... great generality and importance are known.

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DTN and Future Internet Research

DTN-related R&D proposals in NSF NeTS FIND (Future Internet Design)Postcards from the Edge: A Cache-and-Forward

Architecture for the Future Internet Roy Yates, Dipankar Raychaudhuri, Sanjoy Paul, James

Kurose 　 (Rutgers WINLAB; UMass)The-Day-After Networks: A First-Response

Edge-Network Architecture for Disaster Relief Haiyun Luo, Robin Kravets, Tarek Abdelzaher (UIUC)

Transient Network Architecture Robert Kahn, Chaouki Abdallah, Henry Jerez, et al. (CNRI)

Architectural Support for Selectively-Connected End Systems: Enabling an Energy-Efficient Future Internet Mark Allman, Vern Paxson, Ken Christensen, Bruce

Nordman (ICSI, University of South Florida, LBNL)

A general framework for cost-efficient information exchange over discontinuous space and time

As a basis for asynchronous (non-realtime) comm. across very heterogeneous networks

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Our project DTN-based R&D for future network services

For cost-efficient networking in rural and urban life rather than only for exotic environments: Efficient use of limited wireless resources and/or Saving energy

Fully exploiting a combination of diverse network techniques for non-realtime comm.: Integrated Wired and Wireless Network Platform Universal identifier and Late binding Store-(carry-)forward message delivery A variety of Space and Time and Freq. (cognitive ratio) resource

scheduling schemes

Population

density

Bandwidth

narrow

broad

Optical /ADSL

Ｓａｔｅｌlｉｔｅ

VOIP

WIFI WIFI

WIFIWIFI

WIFIWIFI

Cellular phoneCHAT

E-Mail

WEB

AUDIO

STREAMING

IPTV

UPDATE

DOWNLOAD

urbanrural rural

Store-carry-forward scheme based

network infrastructure

Population

density

Bandwidth

narrow

broad

Optical /ADSL

Ｓａｔｅｌlｉｔｅ

VOIP

WIFI WIFI

WIFIWIFI

WIFIWIFI

Cellular phoneCHAT

E-Mail

WEB

AUDIO

STREAMING

IPTV

UPDATE

DOWNLOAD

urbanrural rural

Store-carry-forward scheme based

network infrastructure

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Our project (cont.)

1. Integrated Multi-network Data Transfer Proxy Agent and its Protocol– Large data transfer over multiple inferior networks

between intermediate nodes (proxy agents)– Integrating wide-area, stable but low-speed networks

and narrow-area, high-speed but unstable, intermittent networks• WiFi, Cellar, Satellite, WiMAX,...

– Separating data transmission flows and control flows 2. Store-Carry-Forward Based Access Network

Infrastructure– Virtual Segment (VS): a virtual access network along

roads supporting non-realtime large data exchange– Integrating short-range wireless comm and long-range

wired/wireless infrastructure based on store-carry-forward scheme by vehicles (buses, cars, trains, ...)

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Internet

upload to server download from server

control flow

data flow

frequent disconnection

(e.g. in a rural area)

e.g. satellite link

mobile sender

server

relay function

(e.g. in a high-speed moving vehicle)

leaky or heavily varying bit rate

time

time

avai

labl

e bi

t rat

e

e.g. WiFi service inside a car

receiver

retransmission or rate control,address notification

detection of reachable I/F

interworking with wireless gateway node

file to be transferred

A Concept of Integrated Multi-network Data TransferIntegrating wide-area, stable but low-speed networks and narrow-area, high-

speed but unstable, intermittent networks (WiFi, Cellar, Satellite, WiMAX,..)As a new transport protocol between Proxy Agents, especially by separating

data transmission flows and control flows

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Emergency networking in Disaster– by Wifi AP at balloons and satellite

comm.Integrated Multi-network Data Transfer Proxy Agent

antenna on car BGAN EXPLORER

WiFi

Town Office

An application-level Experiment (Plan)

WiFi

Integrated Multi-network Data Transfer Proxy Agent

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land sea

island

ＢＮ

ＢＮ

ＢＮ ＢＮ

ＢＮＢＮ

ＢＮ

ＢＮＢＮ

ＢＮ

Virtual Segment 1

road

Virtual Segment 2

Virtual Segment 3 Virtual Segment 4

ＢＮＢＮ

SMN

SMN

SMN

Copyright © 2009 National Institute of Information and Communications Technology (NICT) All Rights Reserved.

SMN

SMN

SMN: Segment Management Node

A Concept of Virtual Segments Divide the communication area to some virtual segments

（ VSs) In a VS, messages are transferred in a SCF manner by vehicles Take a shortcut between VSs via connected links

10Copyright © 2009 National Institute of Information and Communications Technology (NICT) All Rights Reserved.

Schematic description of VS

Virtual Segment

Core Network

Base Node (BN)Stationary gateway that comm. with and controls the relay node passing near to the BN and also stores the data to be collected and delivered.

Virtual Segment

Geographical region surrounded and delimited by one or more BNs along the roads.

Relay Node (RN)Vehicle that travels along roads and has the ability to store, carry, and forward data from/to correspondent node nearby.

Correspondent Node (CN)Each stationary or mobile comm. user.

ＣＮ

ＲＮ ＢＮ ＢＮ

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Core Network

Ｎ１

App. Server

Virtual Segment

Wired/Wireless Persistent Connection

ＢＮ１

Internet

ＢＮ２

1. User N1 wants to send a request message (REQ) to Internet

2. Car R1 crossing BaseNode BN1 acts as a relay in this VS3. When R1 approaches N1, REQ is passed to N14. When R1 approaches BaseNode BN2, REQ is passed to

BN2

REQ

Ｒ１ REQ

Message exchange between VS and Internet

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Core Network

Ｎ１

VS

ＢＮ１

Internet

ＢＮ２

5. BaseNode BN2 sends REQ to the destination (the application server) on the Internet though a core network

6. A reply message (REP) is sent to both BN1 and BN27. When R2 approaches BN1, REP is passed to R28. When R2 approaches N1, REP is passed to N1, the origin

REQREP REPＲ２ REP

App. Server

Wired/Wireless Persistent Connection

Message exchange between VS and Internet (cont.)

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An image of deployment of Virtual Segment

100m

Copyright © 2009 National Institute of Information and Communications Technology (NICT) All Rights Reserved.

A field trial is being planned on December 2009 at Iizuka city.

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14

Traffic congestion information advertisement (traffic information, accident information )

２． Forward info. to each BN inner segment or outer segment via core network.

Internet

BN1

1.Send traffic congestion information to crossing RNs or nearest BN.

RN/CN car accident

An application-level Experiment (Plan)

BN2

RN/CN RN/CN

3. Each RN/CN receives info. from nearest BN or other RNs.

CN

Copyright © 2009 National Institute of Information and Communications Technology (NICT) All Rights Reserved.

Field trial is planning in December 2009

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An image of pre-experiments

Copyright © 2009 National Institute of Information and Communications Technology (NICT) All Rights Reserved.

Pre Field Trial on 25th August 2009 at Fukuoka city.

Correspondent Node is put on the side of the road

Relay Node ( A man riding on a bus with portable pc equipped with wireless comm. device)

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File Transmission Time comparison

0

100

200

300

400

500

1 2 3 4 5 6 7 8 9 10 11 12

Ave

lage

Del

ay T

ime

(min

utes

)

2M10M100M

phone（ analogue ）

phone（ＩＳＤＮ）

ＡＤＳＬ

FTTH

Cell phone(PDC/line ）

Cell phone(PDC/packet ）

cdmaone

W-CDMA

PHS

VS(1km)

VS(5km)

VS(10km)

Assumed VS parametersRelay speed = 36km/hourTraffic = 10 unit/hourCommunication range = 200mData transmission speed = 10Mbps

VS can provide throughput performance comparable to the narrowband media

Can Store-carry-forward be practical?

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Amazon Web Services (AWS) Import/Export – In uploading huge data to the centers, the time

required to prepare and ship a USB to a near AWS site is shorter than that by using a limited Internet connection• http://aws.amazon.com/importexport/

Pigeon Networking– South Africa pigeon 'faster than broadband

(ADSL)‘ for 4GB data transfer across country• http://news.bbc.co.uk/2/hi/africa/8248056.stm

– Homing pigeons get down to business,　 ferrying rafting company photos

• http://www.denverpost.com/news/ci_6209735

Can Store-carry-forward be practical? (cont.)

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Concluding Remarks In Japan, DTN-related research (in NICT) arose in

2006 and have much attention recently NICT is leading In corporation with universities (Osaka-u, U-Tokyo,

Kyutech, Kuwansei Gakuin-U, etc.) Commercial Interest slowly increasing...

The current NICT project (2009-2010) aims atIntegrated Wired and Wireless Network Platform as cost-efficient networking platform for non-real-

time, asynchronous, and large-sized data comm. In the next project circle from 2011, DTN, other

wireless-related research including cognitive radio, and Future Internet research may be (hopefully) more collaborated in both NICT and Japan.

Copyright © 2009 National Institute of Information and Communications Technology (NICT) All Rights Reserved.