In the context of 5G mobile networks, several new use cases with various requirements with respect to throughput, latency, coverage, etc., should be addressed. To avoid deployment of separate networks for each of the use cases, the concept of network slicing has been introduced, where several logical networks share a single physical network. However, the accommodation of networks with diverse requirements in a single physical network is a new challenge. In this work, we study the effects of a mapping layer, which supervises the network over a service area and manages the allocation of radio resources to slices to guarantee their target service requirements. To do so, we propose an adaptation algorithm based on minimizing deviations from slice requirements. The results show that by utilizing the mapping layer, the resources can be shared efficiently and fairly and the deviations of Key Performance Indicators (KPIs) from the Service Level Agreement (SLA) targets are reduced compared to distributed control methods that are typically used in legacy and current cellular systems.