A Multi-Service Model of Resources With the Neighboring Choice of Allocation Units

Abstract

This article discusses a discretized model of resources to which a mixture of multi-service traffic streams is offered and the connections of individual traffic classes that require a large number of allocation units are always executed using adjacent allocation units. The necessity of occupying the adjacent allocation units is typical, for example, for elastic optical networks, in which these units are termed frequency slots. The present article proposes a new occupancy distribution specially designed for these systems. The new occupancy distribution discussed in the article is based on the approximation of the service process by a reversible Markov process. A particular attention is given to the method for the calculations of the so-called conditional transition probability of the transitions between neighboring states in the Markov process. The analytical results of the modeling are compared with the results of simulations of corresponding network systems.

Analytical Model of a Single Link of Elastic Optical Networks

“…In Section VI, the results of the analytical modeling and the simulation data for a selected number of resources that allocate neighboring serviced FSUs of particular calls are compared and evaluated. In addition, the proposed method is compared with the method [18]. Section VII sums up the most important results of the present research study.…”

“…Let us denote by R SEQ , as in [18], the resources in which connections can be established exclusively in the neighboring FSUs. The neighboring FSUs required for a new connection to be set up are chosen randomly from among all possible sets of free FSUs.…”

“…The model [17], however, has not been designed for analysis of single links in EONs. [18] proposes the first, approximated model of multiservice resources for EONs, in which neighboring FSUs are always used to set up connections. This model is based on the assumption that in a given state of the service process, the occupied FSUs that belong to already serviced connections are allocated randomly and do not take into consideration their immediate neighborhood.…”

“…The present article proposes therefore a new model that can help increase the accuracy of the results for mixtures of call streams that are characterized by large differences in demanded FSUs. In the model proposed --unlike in the model [18] --the initial assumption is that, in a given state of the service process, the occupied FSUs that belong to already serviced connections are arranged in a way that takes into consideration their neighborhood (mutual location). For thus arranged busy FSUs, the probability of finding free FSUs that are located next to one another, in the number defined by a new connection of a given class, is then determined.…”

“…According to the authors' knowledge, apart from [18] and the model presented in this article, there are no works on models taking into account the occupation of neighboring FSUs and enabling the determination of different characteristics (occupancy distribution, blocking probability) in a single EON network link.…”