COOPERATIVE COMMUNICATIONSA NEW PARADIGM FOR WIRELESS NETWORKING?

David Goodman

Wireless Internet Center for Advanced Technology (WICAT)

Polytechnic University

CHALLENGES OF WIRELESS NETWORKING

Bandwidth

Energy

Mobility

CELLULAR PARADIGM

LICENSED RADIO SPECTRUM

FIXED NETWORK INFRASTRUCTURE

ANYTIME, ANYWHERE

SYMMETRIC CHANNELS

WI-FI PARADIGM

UNLICENSED RADIO SPECTRUM

INFRASTRUCTURE or AD HOC

HOT SPOTS

ASYMMETRIC CHANNELS

WI-FI vs. CELLULAR

Isolated coverageLow mobilityInterference

PowerCost

Bit ratePowerCost

Ubiquitous coverageMobility

Infrastructure

WI-FICELLULAR

WI-FI + CELLULAR

NOKIA: OWLAN

QUALCOMM: HOT-SPOT + CELLULAR BRIDGE

LUCENT: HAND-OFF (SEAMLESS CONNECTIONS)

COOPERATIVE COMMUNICATIONS: INFRASTRUCTURE + AD HOC

NETWORK EFFICIENCY

MSC

THEORETICAL INSIGHTS

Illinois: In dense ad hoc networks, throughput constant (thpt/node 0)

U. C. Berkeley: In dense ad hoc networks with moving terminals thpt/node constant (thptinfty)

Rutgers: Hot spots + mobility + P2P = fast, efficient dissemination

COOPERATIVE COMMUNICATIONSRESEARCH GOALS

EXPLOIT MOBILITY

EXPAND BANDWIDTH

EXTEND BATTERY LIFE

PROMOTE RELIABILITY, RESILIENCE

GEOGRAPHY OF INFORMATION

Where? Local, regional, everywhere

When?Instantaneous, recent, long-term

Who?Individual, group, general interest

GEOGRAPHY

USERSSIGNALS INFORMATION

+ +LOCATION LOCATION LOCATION

GEOGRAPHY

INFORMATIONRELEVANCE

LOCATIONTIME

POPULATION

ENVIRONMENT

RADIO PROPAGATIONINTERFERENCE

+ PEOPLE &MACHINES

LOCATIONMOTIONDEVICES

INFORMATION NEEDS

+

USERSSIGNALS INFORMATION

7DS Columbia Application Infostations Rutgers/Poly

CAHAN NJIT Network

Cooperative coding Poly Physical

COOPERATIVE COMMUNICATIONSRESEARCH PROJECTS

7DS COLUMBIA

Peer to peer data sharing

Efficiently deliver information of local interest

Conserve power

P2P & CLIENT-SERVER

INFOSTATIONS + AD HOC

Collection of hot spots feed data to terminals

Terminals in motion disseminate data

Two-way transactions required

CAHAN - NJIT

Efficient routing between terminals and BS

Reduce power, increase bandwidth efficiency, signal quality

k

CONGESTION

Dead Spot

DEAD SPOTS

COOPERATIVE CODING POLY

Path diversity combats fading

Reduce power, increase signal quality

M1

BS

M2

COOPERATION BETWEEN 2 TERMINALS

STRATEGY EXAMINE ENTIRE SYTEM - ALIGN

INFORMATION URGENCYLOCALIZATIONUSERS

ENVIRONMENT SIGNAL PROPAGATIONNETWORK ACTIVITY

TERMINALS LOCATIONMOTIONPOWER SUPPLY

NETWORK CELL-LANAD HOC/INFRA

CHALLENGES

EACH TERMINAL SUPPLIES BANDWIDTH

ADDED TERMINALS REDUCE POWER NEEDS

INCENTIVES TO COOPERATE

SECURITY

“a highercalling”