Improving Event Throughput of Wireless Sensor Networks
Wireless sensor networks have broad applications in habitat monitoring, battle field surveillance and disaster relief. While sensors normally operate under light load, they may be suddenly activated by abrupt events such as enemy attack or fire spread. In such cases, large volume of data may be generated and transmitted to the sink within a short period, which demands high throughput transmission channels to transfer the bursting data in a timely fashion. we try to improve the throughput of sensor networks by utilizing the unique tree structure that is naturally formed in data collection of a sensor network. In this hierarchical tree structure, each intermediate node collects data from multiple sources and forwards data to a node at higher layer. The basic unit consists of one parent(receiver) and multiple children (senders). By adapting the CSMA, which is originally designed for many-to-many communication, to this many-to-one communication pattern, we can enhance the communication performance at the link layer of wireless sensor network, and therefore improve the communication throughput. We evaluate the receiver-centric protocol on both MICA2 and Tmote sensor motes. Our experiments shows that the data transfer throughput can be significantly improved.

  • Media access scheduling in sensor networks: We have implemented the Media access scheduling program in MICA2 sensors to reduce channel collisions. This program is specially designed based on the tree structure that are naturally formed in data collection of a sensor network, and therefore outperforms other MAC protocols designed for general purposes.
  • Efficient packet retransmission in sensor networks: The efficient packet retransmission program has been implemented in MAC layer of MICA2 sensors. The efficient packet retransmission can recover lost packets without reliance on acknowledgments (ACKs), and therefore outperforms other ACK-based retransmission mechanisms.


  • C. Wang, E. Lee, and L. Xiao, Receiver-Centric Data Transportation for Sensor Networks, under submission.
  • C. Wang and L. Xiao, Improving Event Throughput for Wireless Sensor Networks," DCOSS 2007.