Demo Abstract: TOSSDR: TinyOS on any Physical Layer implemented in Software De ned Radio

Research in wireless physical and link layers is restricted in many cases by the transceiver chip hardware, with its specic limitations, the software drivers for the hardware, which are sometimes only available in binary format and not modiable. Software Dened Radios oer the possibility to do research in those layers without the showstoppers of the chip and/or the driver. TinyOS has given the ability to do research in link layer protocols on an inexpensive platform, the limitations with regard to the physical layer however are however remaining present. The research presented here allows for physical layer research by interfacing TinyOS to the GNU Radio/USRP platform. The physical layer in use here is IEEE 802.15.4, other physical layers implemented in GNURadio might be used as well. Software Dened Radios are radios that are handling the physical layer mod-ulation/demodulation and en-/decoding in software and can thus be changed easily and possibly even at runtime. GNU Radio [1] is an open source Software Dened Radio, which already contains many of the implementation blocks needed for handling several physical layers. The main hardware platform supported is the Universal Software Radio Peripheral (USRP) [2]. The TinyOS community is already providing a large set of open-source protocols and additionally provided researchers with many inexpensive platforms. Software Dened Radios as an additional target platform for TinyOS can allow for physical layer research and be of benet to the TinyOS community. The TinyOS SDR target (TOSSDR) is derived from TOSSIM and just like TOSSIM a make subtarget of the MICAz target. Applications that are to be run on the SDR can be built using 'make micaz sdr'. The architecture of TOSSDR is depicted in Fig. 1. The application layers of a TinyOS application remain unmodied, while the ActiveMessage layer and all lower layers have been modied to adapt to the SDR. This adaptation was achieved by removing all chip dependent functionality from the respective modules. The main changes have been accomplished in SdrTransmit and SdrReceive, which are derived from CC2420Transmit/Receive. In the SdrTransmit component callbacks, that have been registered by the sdr2tos.py main executable, give the data that is to be transmitted to the SDR and initiate the transmission. The SdrReceive component exposes the functions to be called for receiption of packets by SWIG interfaces. The script sdr2tos.py connects the two software stacks together by initiating the TOSSDR application (in the same way a TOSSIM in