Most of the contemporary research in wireless networks is primarily based on simulations or small scale inhouse experimental setups that are highly customized for the experiment and hence difficult to re-use. Although, this may be suitable for smaller experiments, it is very difficult to adapt this setup to other experiments without writing extensive scripts for controlling and collating the results of the experiment which may take up more time than the actual experiment in some cases. The main hindrance to facilitating rapid experimentation is the lack of a flexible framework that will allow researchers to conduct several different experiments with ease and to be able to repeat them as often as necessary for statistical consistency. The above considerations motivated the ORBIT testbed project, which is a multi-user experimental facility to support research on next-generation wireless networks. In this paper, we describe the software architectural framework of the testbed to facilitate repeatable wireless experiments and provide essential services to choreograph experiments as well as automate the routine tasks of measurement collection. This will allow researchers to focus mainly on algorithms and data analysis. In particular, we address key considerations to be taken into account such as capturing all experiment parameters to facilitate repeated experimentation as well as a framework for data collection. We also present experimental results from sample experiments performed using the grid along with key results and observations.