Resource pooling in network virtualization and heterogeneous scenarios using Stochastic Petri nets

Wireless cellular networks are undergoing severe changes due to the ever increasing demand of data rate. Additionally, the demand is more and more heterogeneous (imbalanced) in time and space. Sudden peaks in demand at a certain location have to be absorbed by the network. While operators traditionally over-provisioned their own separate network capacity in order to reduce the blocking and overload probabilities, this approach seems no longer economically viable. Instead, the idea of network virtualization (NV) emerged. One aspect of NV is that resources from all operators are pooled together. Shared and virtualized resources can be better distributed among all users compared to having separate subsets of users to separate subsets of resources. This holds especially if the demand is imbalanced among the operators, as shown in this paper. In this paper the stochastic Petri net (SPN) paradigm is used to provide with a compact model of NV resource pooling (RP). In contrast to the equivalent but tedious analysis of Markovian systems the SPN approach allows a quick numeric performance evaluation with tool support, thus olfering a strong modeling advantage. The scenarios analyzed here are networks of separate operators and resources, compared to one virtualized network. In a second step the scenario includes heterogeneity in demand, i.e., a load imbalance between the providers and results show much higher gains in this unbalance.