Tianqiang Li

Graduation Semester and Year




Document Type


Degree Name

Master of Science in Computer Science


Computer Science and Engineering

First Advisor

Yonghe Liu


Wireless sensor networks consist of a certain number of autonomous devices with sensor, every device has certain detection functionality like light, temperature pressure etc. Communication by using the radio frequency make these spatially distributed devices feasible to oversee the activities in a large scale of area/space. 802.15.4/ZigBee networks are slated to run in the unlicensed frequencies. It is a packet-based radio protocol aimed at very low-cost, battery-operated widgets and sensors that can intercommunicate and send low-bandwidth data to each other. This thesis covers the content of a software solution of data management for an 802.15.4 networks. Its main contribution lies in it grounds a scalable and extendable infrastructure for current and future developments to depend on, enabling users to manage the distributed sensor data across the diversified and spacious ZigBee network. Some unique technologies are proposed according to the specific hardware embedded environment, such as cyclic queue, storage structure of RAM+Flash memory, Dynamic binary search etc. Some improvement solutions are also implemented in an attempt to fill the gaps in functionalities of ZigBee networks such as TCP/IP stacks built onto ZigBee protocols. Some advanced design ideas are also presented such as browser-based user interface, communication via standard protocol (HTTP); Some software implementations are accomplished for the first time without former references such as the immigrating the RTX51 tiny from standard 8051 CPU to ChipCon2430 CPU. The infrastructure that we proposed consists of the sensor data collecting subsystem, data storing subsystem, data query algorithm and subsystem, radio frequency intercommunication subsystem and browser based user accessing interface. Sensor data collection and storing system will periodically save the sampled value from sensor to the memory system and later to the permanent flash memory. Data query subsystem will provide an efficient approach to locate the data to be queried among large number of stored data. Radio frequency intercommunication subsystem is in charge of the radio frequency communication between devices, to delivery back and forth for the query request and response is the one of the major duties in this subsystem. The user accessing interface supports the users to submit query requests in the browser with the standard http link address in users' personal computer.


Computer Sciences | Physical Sciences and Mathematics


Degree granted by The University of Texas at Arlington