ubibay an auction system for mobile multihop ad-hoc networks * hannes frey, johannes k. lehnert,...
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UbiBayAn auction system for mobile multihop ad-hoc networks*
Hannes Frey, Johannes K. Lehnert, Peter SturmSystem Software and Distributed Systems, University of Trier
* This work is funded in part by DFG, Schwerpunktprogramm SPP1140 “Basissoftware für selbstorganisierende Infrastrukturen für vernetzte mobile Systeme”
Assumptions
Metropolitan sized networking Mobile devices
Wireless communication facilities
Direct communication only within communication range
Unpredictable topology changes due to mobility Network partitions Permanent link failures
The UbiBay application People sell low-value goods “in their neighborhood”
Too much effort to put it on eBay Enough potential buyers locally Need for “cheap” communication
Exchange of goods By appointment Supermarkets etc. as trustworthy third parties Quick auctions at popular places: people have goods with them
Auctions of low-value goods well suited for ad-hoc networks Decentralized and self-organizing Restricted geographical area Not time-critical
The UbiBay application
Start new auctions Describe auction Define minimum bid and duration
See a list of all known auctions View details:
bids, duration, description Participate in auctions
Define maximum bid Notifications
of being outbid of finished auctions
UbiBay
Auctions running:
Bidding on:
Auctioneer for:
10 CD-Rs J. Doe $5.5Details
Bid
Title Auctioneer Bid
Title Auctioneer Bid Max
Dilbert book S. Smith $7 $10 Bid
Dilbert book S. Smith $7Details
Bid
Title #Bids Leader Bid
Calendar 3 B. Stevens $1.5
The UbiBay application
Devices communicate through messages Auction/Description/Notification message Dissemination of messages with PeriodiCast
UbiBay application on all mobile devices Redistributes received messages Distributed maximum computation Handles bidding up to maximum bid Protects maximum bid
The UbiBay application Reputation system
Buyer and seller rate each other Differentiate personal and community ratings Use counters to measure reliability Disseminate ratings using PeriodiCast Follows approach by Schneider et. al., 2000
Security Ensure integrity of messages Cope with replay and
suppression of messages Decentralized and self-organizing CA
PeriodiCast Use device discovery for background
information dissemination Fill unused parts of MTU Distribute information over several
discovery messages Handle fragmentation Timeouts avoid collisions/congestion
Applications reserve buffers/ports Guaranteed priority Notification after dissemination
Allows parallel use of other communication patterns
unusedDevice discovery
MTU
IDPort
IDPort
IDPort
priority based scheduling
Application 1 Application 2bu
ffer
buff
er buff
er
Enhancements/Future work
Handle message suppression Observing mechanism: neighbors detect
malicious devices
Allow mobility of auction agents Marketplace communication pattern
Position-based routing
Protect the maximum bid through secret sharing
Implement UbiBay on real hardware Field test with students