Universität
Karlsruhe
GERMANY
Vertical Integration of Incentives
for Cooperation
The Second Mediterrean Workshop on Ad Hoc Networks
June 25-27, 2003 – Mahdia, Tunisia
Philipp Obreiter, Michael Klein
Universität Karlsruhe, Germany
Institute for Program Structures und Data Organization
DIANE Project
http://www.ipd.uni-karlsruhe.de/DIANE
1/16
Motivation
B
D
A
wants to print
a document
C
is
connected
to a printer
Questions:
• Why should D offer a printing service to A?
• Why should B and C forward packages from A to D?
2/16
Autonomy and Elementary Cooperation
Typically in Ad hoc Networks:
Autonomous devices
 devices are free to cooperate or not
 tend to be uncooperative due to
scarceness of resources (e.g. battery power)
 cooperative behavior must be stimulated
action
Agent
Principal
remuneration
3/16
Conceptual Layering
User Interface
User Interface
Application
Application
Discovery
Discovery
device A
Transport
device B
Transport
Network
Network
Link
Link
autonomy
border
4/16
Asymmetric Cooperation Patterns
Example on the network layer
inherent agent
amasses remunerations
a
c
b
d
inherent principals
runs out of remunerations
 Vertical trading of remunerations
5/16
Overview
• Vertical interaction
• Generic model combining
vertical & horizontal collaboration
• Applicability issues
6/16
Vertical Interaction
Conventional vertical interaction
• (n+1) PE relinquishes resources to
• (n) PE in order to consume its services
(n+1) Protocol Entity
resources
services
(n) Protocol Entity
7/16
Vertical Trading of Remunerations
In the presence of incentive schemes
• a vertical flow of remunerations is required
(n+1) Protocol Entity
remuneration
(n) Protocol Entity
inh. agent
8/16
inh. princ.
Introductory Example (1)
A PDA user repeatedly prints documents
PDA
Printer
User PE
User PE
Appl. PE
Appl. PE
Vertical trading of remunerations:
• The PDA user pays for printing documents
• The printer owner is refunded for the operation costs
9/16
Introductory Example (2)
The communication between the PDA
and the printer is routed
PDA
Router
Printer
User PE
Appl. PE
Netw. PE
10/16
Appl. PE
Netw. PE
Netw. PE
Introductory Example (3)
Combined view:
PDA
Router
Printer
User PE
User PE
Appl. PE
Appl. PE
User PE
Netw. PE
11/16
Netw. PE
Netw. PE
The Generic Model of Stimulated Cooperation
The generic model combines
• Vertical interaction and trading
• stimulated cooperation
Device A
12/16
Device B
(n+1) PE
(n+1) PE
(n) PE
(n) PE
Problems with Vertical Trading
Main Problem
Protocol layers are encompassed by different
incentive schemes:
•
•
different remuneration types (“currencies”)
closure constraints of incentive schemes
 Then, protocol entities cannot vertically trade
remunerations
13/16
Vertical Trading of Remuneration in Practice
Is vertical trading of remunerations implementable?
Device A
14/16
Device B
(n+1) PE
(n+1) PE
(n) PE
(n) PE
Conclusion
Summary
• cooperation beyond autonomy borders requires incentives
• vertical trading of remunerations prerequisite for the
effectiveness of the incentive scheme
• we proposed a generic model that combines vertical and
horizontal collaboration
• illustrated how vertical trading of remunerations is
implemented
Future work
• conception of appropriate transaction protocols that
support vertical trading of remunerations
• implement the concept
15/16
Thank you!
Thank you for your attention!
More information on our project web page:
http://www.ipd.uni-karlsruhe.de/DIANE/en
Are there any questions?
16/16
Elementary Cooperation
action
Agent
Principal
remuneration
Application Layer
Network Layer
service
forwarding
Provider
Consumer
check
17/16
Router
Sender
reputation
Account Based Incentive Schemes: Properties
Remuneration mechanism
•
•
•
•
every entity possesses an account
accounts stored on virtual banks
principal issues a check
agent accesses a virtual bank in order to credit its account
Implementation
• requires static trust mechanisms
• virtual banks managed by dedicated devices
• banker nodes
• accessibility?
• accounts distributed to account holders
• tamper resistant hardware
18/16
Reputation Based Incentive Schemes: Properties
Remuneration mechanism
• principal adapts agent's reputation according to its action
• agent might decrease principal's reputation
• agent only cooperative if principal has good reputation
Implementation
• couple trust and remuneration
• local views of reputation may be
• kept local
• shared, i.e., disseminated
• increases effectiveness
• introduces further opportunities for misbehavior
• requires stable or localized cooperation patterns
19/16
Vertical Interaction
Conventional vertical interaction
• (n+1) PE relinquishes resources to
• (n) PE in order to consume its services
(n+1) Protocol Entity
resources
services
(n) Protocol Entity
Resource assessment
• makes costs for service provision transparent
• provides a basis for decision making
20/16
Heterogeneity and Integration
What happens if protocol layers belong to
different incentive schemes?
•
•
vertical trading of remunerations goes beyond
incentive scheme borders
protocol entities cannot vertically trade
remunerations
Integration of incentive schemes has to cope
with heterogeneity with regard to:
1. incentive schemes and encompassed layers
2. incentive schemes and incentive patterns
21/16