Patrick Wüchner

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This paper proposes a retrial queueing model with the finite number of sources to evaluate the performance of spectrum renting in mobile cellular networks. The model incorporates necessary ingredients such as the finite number of subscribers, their impatience and a queue for the outbound service. To consider the specific feature of spectrum renting and the(More)
To achieve a preferred global behavior of self-organizing systems, suitable local interaction strategies have to be found. In general, this is a non-trivial task. In this paper, a general method is proposed that allows to systematically derive local interaction strategies by specifying the preferred global behavior. In addition, the resulting strategies can(More)
Motivated by the need for performance models suitable for modeling and evaluation of wireless sensor networks, we introduce a retrial queueing system with a finite number of homogeneous sources, unreliable servers, orbital search, and unreliable orbit. All random variables involved in model construction are assumed to be independent and exponentially(More)
Since the entities composing self-organizing systems have direct access only to information provided by their vicinity, it is a nontrivial task for them to determine properties of the global system state. However, this ability appears to be mandatory for certain self-organizing systems in order to achieve an intended functionality. Based on Shannon’s(More)
Some cellular automata are able to solve classification problems on their initial configuration by building globally visible structures. However, no formal measures exist yet for describing or detecting this behavior in general. The lack of such formal methods often leads to quite observer-dependent discussions of emergent computation. In this paper, we(More)
We consider a retrial queueing system with a finite number of homogeneous sources of calls and a single server. Each source generates a request after an exponentially distributed time. An arriving customer finding the server idle enters into service immediately; otherwise the customer enters into an orbit. The service times are supposed to be exponentially(More)
We present an example of the use of analytical models to predict global properties of large-scale information technology systems from the parameters of simple local interactions. The example is intended as a first step towards using complex systems modeling methods to control self-organization in organic systems. It is motivated by a concrete application(More)