Yanjun Sun

Demo: Achieving robust sensor networks through close coordination between narrow-band power line and low-power wireless communications

Sensor networks are increasingly available in home and industry automation applications. The use of battery-powered wireless sensor nodes eases network deployment, but the dynamic wireless medium, along with energy and bandwidth constraints, poses a great challenge to achieve a robust sensor network only with these nodes. In this demonstration, we present a hybrid sensor node platform equipped with a narrow-band power line communication (PLC) transceiver and a low power RF transceiver, which closely coordinates the two transceivers to improve robustness of a sensor network. Our platform is composed of the TelosB running Contiki and a PLC module that supports several latest narrow-band PLC standards. In addition, we have extended the COOJA simulator of Contiki to support this hybrid sensor node platform in order to aid protocol designs in the context of large sensor networks.

Mechanisms for coexistence of collocated WLAN and bluetooth in the same device

In this paper, we investigate the performance of WLAN power save and active mode for collocated WLAN and Bluetooth technologies in the same device. We present a simple, yet accurate, analysis for these mechanisms and also show simulation results. We identify practical issues with these mechanisms and propose an algorithm that reduces overhead in the network from 30% to 10%.