MOSEL - MOdeling Specification and Evaluation Language

In this paper the new model description language MOSEL (Modeling Specification and Evaluation Language) - developed at the Institute for Operating Systems at the University of Erlangen-Nuernberg - is described using many examples. To evaluate the performance of systems, like computer systems, networks, production lines and so on, the system has to be specified. Currently there already exist many different performance evaluation tools, which all have different input languages. The input languages for these tools are not only different, but they are also hard to use, since they all have a syntax which is oriented on the characteristics of the tool and not on the system which the user wants to describe. They are comparable with assembly languages for specific processors. The basic idea of the new language MOSEL is, to have only one language which is easy to use and reflects the real structure of the system the user wants to describe. MOSEL could be compared with a higher programming langu..

Generation and Solution of Markov Chains Using MOSES

In this paper the Markov analyzer MOSES (MOdelling, Specification and Evaluation System) and the model description language MOSLANG -- both developed at the Institute for Operating Systems at the University of Erlangen-Nuernberg -- are described using two examples. To evaluate the performance of a computer system the system has to be specified. In this paper the model description language MOSLANG is introduced and applied to some examples. The core of MOSLANG consists of constructs suitable for the specification of the possible states of the system and of RULE constructs which model the state transitions. This specification method is much more compact than other comparable methods and enables the user to specify large systems when he has become familiar with MOSLANG. The Markov analyzer MOSES supports the input of MOSLANG and subsequently creates the Markovian system of equations automatically. For solving this system of equations five different methods are provided. MOSES calculates..

Modeling and Simulation of Markov Modulated Multiprocessor Systems with Petri Nets

Markov modulated processes are very often used to model di erent arrival processes of multiprocessor systems. In this paper a heterogeneous multiprocessor system is presented, which was analyzed and validated by many di erent techniques. The di erent job arrivals of the system are presented using stochastic Petri nets. The calculated performance measures are validated against system simulation. The major problem of each Markov model is the size of the state space which grows exponentially in the system complexity. 1 Introduction/Motivation In the paper of [Kelling93], the determination of an initial checkpoint of the spectral variance analysis i

Scalable Schemes for Mobile Networks with Multiple Services

The introduction of new service categories with different bandwidth requirements, e.g., data and multimedia, to cellular mobile radio networks makes many of the traditional mechanisms unusable or less efficient. The call admission and the handover handling are of the most sensitive issues to this extension. The performance of all services including the traditional voice and the new services can be dramatically affected if no appropriate schemes are used. In this paper, we propose call admission and handover handling schemes for a cellular mobile network that offers two service types: voice and data. The data connections are assumed to transmit at different transmission rates that are integer multiples to that of one radio channel. In the case of congestion, the base station asks the active data connections to reduce their transmission rate in order to provide free channels for the newly arrived request of both service types. This is basically intended for incoming handover r..