As experimentation becomes one of the de-facto approaches for benchmarking, researchers are turning to testbeds to test, review and verify their work. As a result, several research laboratories build wireless testbeds, in order to offer their researchers a real environment to test their algorithms. As testbeds become more and more popular, the need for a managerial tool that will not only provide a unified way for defining and executing an experiment and collecting experimental results, but that will also serve as many users as possible maximizing the utilization of its resources, is growing. In this spirit, we propose a scheme that exploits wireless testbeds functionality by introducing spectrum slicing of the testbed resources. This scheme can be incorporated inside OMF, an already existing wireless testbeds managerial framework, which is widely used by many researchers.