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COOPERATIVE COMMUNICATIONS A 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
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COOPERATIVE COMMUNICATIONS A 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 CELLULAR WI-FI J Ubiquitous coverage Mobility Infrastructure Bit rate Power Cost L Power Cost Isolated coverage Low mobility Interference
WI-FI + CELLULAR • NOKIA: OWLAN • QUALCOMM: HOT-SPOT + CELLULAR BRIDGE • LUCENT: HAND-OFF (SEAMLESS CONNECTIONS) • COOPERATIVE COMMUNICATIONS: INFRASTRUCTURE + AD HOC
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 + + LOCATION LOCATION LOCATION SIGNALS USERS INFORMATION
GEOGRAPHY + + INFORMATION RELEVANCE ENVIRON MENT PEOPLE & MACHINES SIGNALS USERS INFORMATION RADIO PROPAGATION INTERFERENCE LOCATION MOTION DEVICES INFORMATION NEEDS LOCATION TIME POPULATION
COOPERATIVE COMMUNICATIONSRESEARCH PROJECTS 7DS Columbia Application Infostations Rutgers/Poly CAHAN NJIT Network Cooperative coding Poly Physical
7DS COLUMBIA Peer to peer data sharing Efficiently deliver information of local interest Conserve power
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
DEAD SPOTS Dead Spot
COOPERATIVE CODING POLY Path diversity combats fading Reduce power, increase signal quality
COOPERATION BETWEEN 2 TERMINALS BS M1 M2
STRATEGY EXAMINE ENTIRE SYTEM - ALIGN INFORMATION URGENCY LOCALIZATION USERS ENVIRONMENT SIGNAL PROPAGATION NETWORK ACTIVITY TERMINALS LOCATION MOTION POWER SUPPLY NETWORK CELL-LAN AD HOC/INFRA
CHALLENGES EACH TERMINAL SUPPLIES BANDWIDTH ADDED TERMINALS REDUCE POWER NEEDS INCENTIVES TO COOPERATE SECURITY
“a higher calling”