  In many wireless communication networks a common channel is shared by
multiple users who must compete to gain access to it. The operation of the
network by self-interested and strategic users usually leads to the overuse of
the channel resources and to substantial inefficiencies. Hence, incentive
schemes are needed to overcome the inefficiencies of non-cooperative
equilibrium. In this work we consider a slotted-Aloha like random access
protocol and two incentive schemes: pricing and intervention. We provide some
criteria for the designer of the protocol to choose one scheme between them and
to design the best policy for the selected scheme, depending on the system
parameters. Our results show that intervention can achieve the maximum
efficiency in the perfect monitoring scenario. In the imperfect monitoring
scenario, instead, the performance of the system depends on the information
held by the different entities and, in some cases, there exists a threshold for
the number of users such that, for a number of users lower than the threshold,
intervention outperforms pricing, whereas, for a number of users higher than
the threshold pricing outperforms intervention.
