42,476 research outputs found
FAIR: Forwarding Accountability for Internet Reputability
This paper presents FAIR, a forwarding accountability mechanism that
incentivizes ISPs to apply stricter security policies to their customers. The
Autonomous System (AS) of the receiver specifies a traffic profile that the
sender AS must adhere to. Transit ASes on the path mark packets. In case of
traffic profile violations, the marked packets are used as a proof of
misbehavior.
FAIR introduces low bandwidth overhead and requires no per-packet and no
per-flow state for forwarding. We describe integration with IP and demonstrate
a software switch running on commodity hardware that can switch packets at a
line rate of 120 Gbps, and can forward 140M minimum-sized packets per second,
limited by the hardware I/O subsystem.
Moreover, this paper proposes a "suspicious bit" for packet headers - an
application that builds on top of FAIR's proofs of misbehavior and flags
packets to warn other entities in the network.Comment: 16 pages, 12 figure
Cooperation with Defection
The Prisoner Dilemma is a typical structure of interaction in human societies. In spite of a long tradition dealing with the matter from different perspectives, the emergence of cooperation or defection still remains a controversial argument from both empirical and theoretical point of views. In this paper an innovative model is presented and analyzed in the attempt to provide a reasonable framing of the issue. A population of boundedly rational agents repeatedly chooses to cooperate or defect. Each agent’s action affects only her interacting mates, according to a network of relationships which is endogenously modifiable since agents are given the possibility to substitute undesired mates with unknown ones. Full cooperation, full defection and coexistence of both cooperation and defection in homogeneous clusters are possible outcomes of the model. A computer program is developed with the purpose of understanding the impact of parameters values on the type of outcome. Numerous simulations are run and the resulting evidence is analyzed and interpretedPrisoner Dilemma; cooperation; segregation; networks; simulation
A Simple Cooperative Diversity Method Based on Network Path Selection
Cooperative diversity has been recently proposed as a way to form virtual
antenna arrays that provide dramatic gains in slow fading wireless
environments. However most of the proposed solutions require distributed
space-time coding algorithms, the careful design of which is left for future
investigation if there is more than one cooperative relay. We propose a novel
scheme, that alleviates these problems and provides diversity gains on the
order of the number of relays in the network. Our scheme first selects the best
relay from a set of M available relays and then uses this best relay for
cooperation between the source and the destination. We develop and analyze a
distributed method to select the best relay that requires no topology
information and is based on local measurements of the instantaneous channel
conditions. This method also requires no explicit communication among the
relays. The success (or failure) to select the best available path depends on
the statistics of the wireless channel, and a methodology to evaluate
performance for any kind of wireless channel statistics, is provided.
Information theoretic analysis of outage probability shows that our scheme
achieves the same diversity-multiplexing tradeoff as achieved by more complex
protocols, where coordination and distributed space-time coding for M nodes is
required, such as those proposed in [7]. The simplicity of the technique,
allows for immediate implementation in existing radio hardware and its adoption
could provide for improved flexibility, reliability and efficiency in future 4G
wireless systems.Comment: To appear, IEEE JSAC, special issue on 4
Short-run vs. long-run cooperation among the G-20 countries
In a model of repeated games, we determine the conditions under which cooperation is an equilibrium outcome among the G-20 countries. We consider first, that members are uncertain about the lifespan of the G-20. Second, the nature of member countries and their interrelations can change because of shifts in government regimes. Monitoring and peer pressure to comply with the agreements made are necessary if the goals are to achieve cooperation and thereby attain desirable common goals. If member countries are prone to shifting government regimes and governments are not concerned about their countries' reputations, continuous cooperation becomes more difficult.Repeated games, Prisoners’ Dilemma, cooperation, monitoring, reputation
Observation-based Cooperation Enforcement in Ad Hoc Networks
Ad hoc networks rely on the cooperation of the nodes participating in the
network to forward packets for each other. A node may decide not to cooperate
to save its resources while still using the network to relay its traffic. If
too many nodes exhibit this behavior, network performance degrades and
cooperating nodes may find themselves unfairly loaded. Most previous efforts to
counter this behavior have relied on further cooperation between nodes to
exchange reputation information about other nodes. If a node observes another
node not participating correctly, it reports this observation to other nodes
who then take action to avoid being affected and potentially punish the bad
node by refusing to forward its traffic. Unfortunately, such second-hand
reputation information is subject to false accusations and requires maintaining
trust relationships with other nodes. The objective of OCEAN is to avoid this
trust-management machinery and see how far we can get simply by using direct
first-hand observations of other nodes' behavior. We find that, in many
scenarios, OCEAN can do as well as, or even better than, schemes requiring
second-hand reputation exchanges. This encouraging result could possibly help
obviate solutions requiring trust-management for some contexts.Comment: 10 pages, 7 figure
Spatial SINR Games of Base Station Placement and Mobile Association
We study the question of determining locations of base stations that may
belong to the same or to competing service providers. We take into account the
impact of these decisions on the behavior of intelligent mobile terminals who
can connect to the base station that offers the best utility. The signal to
interference and noise ratio is used as the quantity that determines the
association. We first study the SINR association-game: we determine the cells
corresponding to each base stations, i.e., the locations at which mobile
terminals prefer to connect to a given base station than to others. We make
some surprising observations: (i) displacing a base station a little in one
direction may result in a displacement of the boundary of the corresponding
cell to the opposite direction; (ii) A cell corresponding to a BS may be the
union of disconnected sub-cells. We then study the hierarchical equilibrium in
the combined BS location and mobile association problem: we determine where to
locate the BSs so as to maximize the revenues obtained at the induced SINR
mobile association game. We consider the cases of single frequency band and two
frequency bands of operation. Finally, we also consider hierarchical equilibria
in two frequency systems with successive interference cancellation
Dynamic Policies for Cooperative Networked Systems
A set of economic entities embedded in a network graph collaborate by
opportunistically exchanging their resources to satisfy their dynamically
generated needs. Under what conditions their collaboration leads to a
sustainable economy? Which online policy can ensure a feasible resource
exchange point will be attained, and what information is needed to implement
it? Furthermore, assuming there are different resources and the entities have
diverse production capabilities, which production policy each entity should
employ in order to maximize the economy's sustainability? Importantly, can we
design such policies that are also incentive compatible even when there is no a
priori information about the entities' needs? We introduce a dynamic production
scheduling and resource exchange model to capture this fundamental problem and
provide answers to the above questions. Applications range from infrastructure
sharing, trade and organisation management, to social networks and sharing
economy services.Comment: 6-page version appeared at ACM NetEcon' 1
- …