Research
Multi-AP RRM over HD-WLANs
- Duration: October 2007 – Present
- Instructor: Zhisheng Niu (niuzhs [at] tsinghua [dot] edu [dot] cn)
In High-Density Wireless Local Area Networks (HD-WLANs), wireless Access Points (APs) are widely deployed in order to reduce the cellular size and then strengthen signals. In my work, the new generation Multi-AP WLAN architecture and adaptive physical carrier sensing theory are utilized for the development and implementation of a new cross-layer research platform. Within MAC layer, it manages to complete many functions such as frame capturing, pseudo-broadcast, network measurement, interactions between kernel and user space. Within higher layers, embedded servers and an Access Controller (AC) can be used for controlling and scheduling multiple APs through Ethernet, real-time network analysis, and applying Multi-AP related algorithms. The ultimate object is to deploy a high-density testbed with multiple nodes in real environment and demonstrate the gain in several kinds of performances when Multi-AP architecture and its related algorithms are used, compared to traditional Single-AP architecture.
Flexible Low Cost Wireless Sensor Networks
- Duration: March 2006 – Aug 2006
- Instructor: Lin Zhang (linzhang [at] tsinghua [dot] edu [dot] cn)
FLOWS is the abbreviation of Flexible LOw cost Wireless Sensor systems. As its name indicates, FLOWS enjoys the characters of low cost and flexibility. There is a ultra low-power MCU on the board, and an embeded OS is running on it. In this way, MAC and routing protocols and applications can be programmed as needed to fill diversities of scenarios. The radio front-end is another outstanding property of FLOWS. It can switch it working frequency among 433M/866M/913M bands according to the software programmable registers in the MCU. Within each band, there are multiple channels applicable, and this makes it possible for us to implement multi-channel MAC protocols or even frequency hopping protocols by simply software coding in the MCU.
The project is on-going supported in part by China 863 project and several industrial contracts. Several industrial products based on FLOWS node have been released. On major project we contracted lately is the infrastructure security monitoring for the China National Stadium for Beijing 2008 Olympic Games. Two types of wireless sensor nodes, namely, temperature sensors and tension sensors, are deployed permanently on the roof of the stadium, nick named as "the Bird Nest".
Google Mapplet Development
- Duration: July 2007 – September 2007
- Employer: Google Inc., Beijing, P.R.China
In summer of 2007, I passed several strict interviews and became a software engineer intern in Google Beijing. Here I enjoyed a happy time for both interesting work and fun. My project was front-end web application developing gadgets for China Google Map called Mapplet. Google offers a series of API for developers to manipulate the elements on Google Map. What I did is to program some gadgets such as Weather Forecasting and Traffic