Distributed reciprocal-selection-based 'win-win' cooperative medium access and its stability analysis

In this paper, a distributed ’Win-Win’ reciprocal selection- based medium access scheme (DWWRS-MAS) is designed for a cooperative spectrum leasing system hosting multiple licensed transmission pairs and multiple unlicensed transmission pairs. Based on the proposed DWWRS-MAS, the primary transmitter (PT) intends to lease its spectral resources to an appropriate secondary transmitter (ST) in exchange for cooperative transmission assistance for the sake of minimizing its transmit power and simultaneously satisfying its transmit rate requirement. The ST has an incentive to collaborate with the best PT for the sake of minimizing the ST’s transmit power under the constraint of its QoS requirement, whilst simultaneously winning a transmission opportunity for its own traffic. Moreover, based on the matching theory and queueing theory, we analyse the algorithmic stability and the queueing stability of the cooperative spectrum leasing system exploiting our DWWRS-MAS, respectively. Simulation results demonstrate that our DWWRSMAS is capable of providing both considerable energy savings and substantial rate improvements for the cooperative spectrum leasing system hosting multiple licensed transmission pairs and multiple unlicensed transmission pairs

Principles of Physical Layer Security in Multiuser Wireless Networks: A Survey

This paper provides a comprehensive review of the domain of physical layer security in multiuser wireless networks. The essential premise of physical-layer security is to enable the exchange of confidential messages over a wireless medium in the presence of unauthorized eavesdroppers without relying on higher-layer encryption. This can be achieved primarily in two ways: without the need for a secret key by intelligently designing transmit coding strategies, or by exploiting the wireless communication medium to develop secret keys over public channels. The survey begins with an overview of the foundations dating back to the pioneering work of Shannon and Wyner on information-theoretic security. We then describe the evolution of secure transmission strategies from point-to-point channels to multiple-antenna systems, followed by generalizations to multiuser broadcast, multiple-access, interference, and relay networks. Secret-key generation and establishment protocols based on physical layer mechanisms are subsequently covered. Approaches for secrecy based on channel coding design are then examined, along with a description of inter-disciplinary approaches based on game theory and stochastic geometry. The associated problem of physical-layer message authentication is also introduced briefly. The survey concludes with observations on potential research directions in this area.Comment: 23 pages, 10 figures, 303 refs. arXiv admin note: text overlap with arXiv:1303.1609 by other authors. IEEE Communications Surveys and Tutorials, 201

Cooperators Unite! Assortative linking promotes cooperation particularly for medium sized associations

<p>Abstract</p> <p>Background</p> <p>Evolution of cooperative behaviour is widely studied in different models where interaction is heterogeneous, although static among individuals. However, in nature individuals can often recognize each other and chose, besides to cooperate or not, to preferentially associate with or to avoid certain individuals.</p> <p>Here we consider a dynamical interaction graph, in contrast to a static one. We propose several rules of rejecting unwanted partners and seeking out new ones, and study the probability of emergence and maintenance of cooperation on these dynamic networks.</p> <p>Results</p> <p>Our simulations reveal that cooperation can evolve and be stable in the population if we introduce preferential linking, even if defectors can perform it too. The fixation of cooperation has higher probability than that of on static graphs, and this effect is more prevalent at high benefit to cost ratios. We also find an optimal number of partners, for which the fixation probability of cooperation shows a maximum.</p> <p>Conclusions</p> <p>The ability to recognize, seek out or avoid interaction partners based on the outcome of past interactions has an important effect on the emergence of cooperation. Observations about the number of partners in natural cooperating groups are in concordance with the result of our model.</p

Strategic Coopetition of Global Brands: A Game Theory Approach to ‘Nike + iPod Sport Kit’ Co-branding

Co-branding can be implemented by establishing an agreement of strategic coopetition that allows companies to compete and cooperate simultaneously in order to obtain competitive advantages through operational synergy. With this type of agreement, brands enter markets sharing loyal customers they would be unlikely to reach individually. The main advantages associated with implementation of this form of strategic coopetition are the possibility of jointly communicating brand image, reputation and credibility in a global market where consumers tend to have homogeneous preferences and convergent lifestyles. The strategic coopetition between two global brands, Apple and Nike, through development of the ‘Nike+iPod Sport Kit’ product, serves as a benchmark to illustrate the benefits associated with implementation of coopetitive cooperation agreements. From application of the game theory, simulation of a game of strategic coopetition provided results that confirm global brands obtain benefits, albeit not in equal measure, in terms of adding value to the brand image at a world level.Co-branding; Coopetition; Global brands; Growth of brand value.

On Suicidal punishment among "Acromyrmex Versicolor" Cofoundresses: the Disadvantage in Personal Advantage

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Alliance Coordination, Dysfunctions, and the Protection of Idiosyncratic Knowledge in Strategic Learning Alliances

In high technology industries firms use strategic learning alliances to create value that can’t be created alone. While they open their interorganizational membrane to gain new skills and competences, generate new products and services, accelerate development speed, and enter into new markets their idiosyncratic knowledge base may be impaired when knowledge related dysfunctions like the unintended knowledge transfer, asymmetric learning speed or premature closing occur. Within a value approach we examine the interplay of alliance coordination activities that enhance value creation, emerging knowledge related dysfunctions, and formal and organizational protections measures which shall safeguard firms intellectual crown jewels. We tested our hypotheses with a sample of 111 strategic alliances of young technology based Enterprises (YTBEs) with competing partners in high and key technology industries. Our findings suggest that a focal firm’s alliance management is well advised to intensely coordinate the alliance and to be aware of dysfunctional tendencies that erode alliance value. Since organizational protection measures could exaggerate dysfunctional effects they should be deployed very deliberately on a modest level. Formal protections measures, in contrast, seem to aggravate coordination activities’ value creation effect by setting behavioral guidelines. Moreover, an unsuccessful negotiation process of formal protection agreements may allow a deselection of partners that would not obey others intellectual property interests. Finally, we highlight theoretical and managerial implications that arise from these findings. --Strategic Learning Alliance,Protection

Game theory for collaboration in future networks

Cooperative strategies have the great potential of improving network performance and spectrum utilization in future networking environments. This new paradigm in terms of network management, however, requires a novel design and analysis framework targeting a highly flexible networking solution with a distributed architecture. Game Theory is very suitable for this task, since it is a comprehensive mathematical tool for modeling the highly complex interactions among distributed and intelligent decision makers. In this way, the more convenient management policies for the diverse players (e.g. content providers, cloud providers, home providers, brokers, network providers or users) should be found to optimize the performance of the overall network infrastructure. The authors discuss in this chapter several Game Theory models/concepts that are highly relevant for enabling collaboration among the diverse players, using different ways to incentivize it, namely through pricing or reputation. In addition, the authors highlight several related open problems, such as the lack of proper models for dynamic and incomplete information games in this area.info:eu-repo/semantics/acceptedVersio

Forgiver Triumphs in Alternating Prisoner's Dilemma

Cooperative behavior, where one individual incurs a cost to help another, is a wide spread phenomenon. Here we study direct reciprocity in the context of the alternating Prisoner's Dilemma. We consider all strategies that can be implemented by one and two-state automata. We calculate the payoff matrix of all pairwise encounters in the presence of noise. We explore deterministic selection dynamics with and without mutation. Using different error rates and payoff values, we observe convergence to a small number of distinct equilibria. Two of them are uncooperative strict Nash equilibria representing always-defect (ALLD) and Grim. The third equilibrium is mixed and represents a cooperative alliance of several strategies, dominated by a strategy which we call Forgiver. Forgiver cooperates whenever the opponent has cooperated; it defects once when the opponent has defected, but subsequently Forgiver attempts to re-establish cooperation even if the opponent has defected again. Forgiver is not an evolutionarily stable strategy, but the alliance, which it rules, is asymptotically stable. For a wide range of parameter values the most commonly observed outcome is convergence to the mixed equilibrium, dominated by Forgiver. Our results show that although forgiving might incur a short-term loss it can lead to a long-term gain. Forgiveness facilitates stable cooperation in the presence of exploitation and noise