We have implemented a prototype of Papyrus and Jello on USRP GNU Radios. Despite having limited frequency bandwidth and large processing delays, USRP radios are widely available and fully reconfigurable across various protocol layers. We use the USRP implementation as a proof-of-concept evaluation of Papyrus. Each Papyrus device consists of a USRP GNU radio and a laptop running Ubuntu Linux.
Following the GNU Radio software framework, we implemented Papyrus’s distributed OFDMA in C++ and its spectrum sensing in Python. The components of Papyrus are modular, and thus easy to reconfigure/modify. We implemented Jello as a user-level Python program in GNU radios. It interfaces with Papyrus’s C++ code using Swig (see http://www.swig.org) and utilizes Papyrus’s flexible frequency access and robust usable frequency detection.
Figure 4: System architecture of Papyrus + Jello