Wireless Sensor Network for Coal Mining Safety Monitoring

Coalmine is one of the most important industries in China and the safety of mineworkers becomes the first issue for people to consider. We have developed a prototype system for mineworker location and tracking. The system also provides wireless voice communication and anomaly detection. We focus on wireless communication in the tube under mine and location algorithm for moving mineworkers and machines in this system.

We provide a three-layer wireless sensor network in this system. The first layer is over ground and constructed by Ethernet and the data from underground will be transmitted to the local monitor center and be visited from Internet. The second layer is composed by underground stations and wireless stations. The data from the wireless station will be transmitted to the underground station by cable and then to over-ground main station by main cable. Numbers of portable wireless nodes carried by mineworkers compose the micro wireless sensor network. The location and environment information is reported to the wireless stations periodically.

Wireless Sensor Network for Environment Monitoring

We employ indoor test-bed to validate the tied architecture and the novel power-aware cross-layer scheme. The test-bed is set up with nine EASI210 sensing nodes and one EASI500 gateway which are randomly distributed in a room. The default data transmission power is set to -10dBm. The packet size is fixed to 36 bytes.

In Yanxi Palace of the Forbidden City on December 4, 2005, we deployed the prototype system for the first phase. The system contained eight sensing nodes and one gateway. The second phase of deployment began on March 7, 2006, in which the hybrid hierarchical network architecture and the power-aware cross-layer scheme were adopted. The third phase of deployment began on July 25, 2007 in Wumen Palace with 32 nodes. This system keeps alive till now. We extended this system to another palace, Wuying Palace , on March, 2008 with another 26 nodes. The performance is evaluated on three metrics: the lifetime, the mean retransmission times and the packet loss rate of the whole system. Analysis show that the system packet loss rate of our network is largely reduced and the maximum lifetime of nodes is significant extended in comparison with the traditional modules in TinyOS.

Wireless Sensor Network for Remote Health Care

Traditional Chinese Medicine (TCM) can provide an excellent curative effect in medical treatment. The Chinese Pulse Diagnosis (CPD) is an important part of TCM diagnostic methodology. Chinese medicine practitioners believe that the appearance of the pulse can reveal a lot about the health. The inspection of the pulse is a convenient way for disease diagnosis and prediction. The Chinese doctor can analyze five pulse tracing attributes in term of “locations”, “frequency”, “rhythm”, “shape” and “force”, respectively, and then make an evaluation on the health condition. TCM provides powerful approach gathering comprehensive information to evaluate the user's health conditions. Hence it is very useful to combine TCM in the remote medical care.

Intelligent Transportation Systems

The WSN-based traffic information collecting system is comprised of wireless traffic information collection nodes (TICoN), wireless data aggregation node (DAN) and remote traffic monitoring center (RTMC). TICoN nodes collect and process real-time information in a distributed and coordinated fashion. They transmit the results to the DAN node wirelessly. The DAN node transfers the information to the RTMC or uses the information to control the traffic light. RTMC archives this traffic information and takes it as direction when making some strategies.