IEEE Wireless Communications • April 2012 50 1536-1284/12/$25.00 © 2012 IEEE
U SER C OOPERATION IN W IRELESS N ETWORKS
INTRODUCTION
For over two decades, classical game theory
has been intensively applied in wireless net-
working and communications [1, 2]. As wireless
nodes become mobile, more autonomous, self-
organizing, self-configuring, and the access net-
works are more decentralized, the associated
mathematical tools need to be adapted. Since
one-shot game models (cooperative or not) do
not allow to update strategies, do not allow
error corrections, the game theorists have pro-
posed dynamic game theory. These include
stochastic games, evolutionary games, differen-
tial games and their ramifications. Dynamic
game theory is a more appropriate framework
and captures more the behaviors of wireless
networks where randomness, time delays and
uncertainties are present. One of the dynamic
game-theoretic modeling is evolutionary game
theory (EGT). It goes back at least to the
works by Fisher (1930), Hamilton (1964), May-
nard Smith (1972). For more details on evolu-
tionary game dynamics in wireless networks,
we refer to [3]. Many researchers are currently
engaged in developing evolutionary game theo-
ry based schemes in large-scale wireless net-
works that allows to describe evolution of
cooperation, evolutionary network formation,
dynamic network security, evolution of proto-
cols, network neutrality, random graph-based
topology and architectures.
Most of the current research in the field is
restricted to applying standard coalitional game
models and techniques to study very limited
aspects of cooperation in wireless networks. At
the same time, the implementation of coalitional
games in large-scale wireless networks encoun-
ters several challenges such as appropriate mod-
eling, efficiency, stability, signaling reduction,
complexity, fairness, incomplete information and
mobility management.
Dynamic coalitional game is a very promising
tool for designing fair, robust, practical, and effi-
cient adaptive coalitional strategies in wireless
networks where the network conditions evolve
dynamically (i.e., backoff state, channel sate,
arrival of users, departure of users, etc.). The
evolutionary coalitional game modeling is one of
the dynamic coalitional game framework. It is
very powerful framework inspired from biology,
genetics and evolutionary ecology.
As in standard coalitional games, the central
concept of evolutionary coalitional game is that
of coalition, i.e., a subset of players that join
their forces and decide to act together (jointly):
the players form their coalitions to join optimal
payoffs, players from the same group can negoti-
ate collectively. For each subset of players, one
associates a value, generating a function called
characteristic form. In wireless networks, one
needs to take into consideration the cost of com-
munications [4] and costs of bargaining for a join
decision so that the value will be a function of
the benefit and the cost.
In this article, we overview the evolutionary
ingredients that constitute the fundamentals of
evolutionary coalitional games as well as their
potential applications in wireless networking and
communications. Our aim is to provide a better
understanding of the current research issues in
this emerging direction. We also attempt an
investigation into pertaining design constraints
and outline the use of evolutionary dynamics
tools to meet certain design objectives.
The remainder of the article is organized as
follows. In the next section we present the basic
MANZOOR AHMED KHAN, TECHNISCHE UNIVERSITÄT BERLIN
HAMIDOU TEMBINE, ECOLE SUPÉRIEURE D’ELECTRICITÉ
A THANASIOS V. V ASILAKOS, UNIVERSITY OF WESTERN MACEDONIA
ABSTRACT
The current state of the art of evolutionary
coalitional game theory in wireless networking
and communications is captured in this article,
where solutions are discussed under their related
applications. Fully distributed algorithms for
global optima in network selection games are
examined. Then the problem of dynamic net-
work formation and evolutionary coalitional
games in wireless networks are investigated. This
article also points out the open research issues,
new interests, and developments in this interdis-
ciplinary field.
E VOLUTIONARY C OALITIONAL G AMES : D ESIGN AND
C HALLENGES IN W IRELESS N ETWORKS
This work was started when the first author was visiting
Supelec, France.
The authors discuss
the current state of
the art of evolution-
ary coalitional game
theory in wireless
networking and com-
munications, and
propose solutions
under their related
applications.