Quantitative Comparison of Radio Environments for T-Ring Test System

T-Ring is a new integrated wireless testbed developed for scalable and reproducible evaluation and simulation of various wireless networks. Since it spans a large geographical area, the effect of signal propagation is truly real, which is a key required feature for some wireless research. For the purpose of comparing experimental results of T-Ring with similar experiments conducted on other real-world networks, quantitative comparison of the radio environments is imperative. This paper introduced a comparison method by calculating the similarity degree of the CDFs of a specific characteristic of two radio environments. Also we propose an expression of synthesized similarity degree which is a linear sum of similarity degree value of different channel characteristics. The comparison in this paper are currently made from the aspect of RSSI and RMS delay spread because of their close relation with large-scale fading and small-scale fading respectively. The contribution of each characteristic to the synthesized similarity degree is analyzed and the process of determining the weight factor of each characteristic with a pure simulation is presented. The numerical result demonstrates the feasibility of the comparison method and also shows that RMS delay spread is more effective than RSSI to show the difference of radio environments for cells with same or different sizes.