University: University of Texas at Arlington
Professor: Qilian Liang
Department: Department of Electrical Engineering

Project I: Latency Aware and Energy Efficiency Tradeoffs for Wireless Sensor Networks

The performance evaluation is one the most important research topics of the Wireless Sensor Networks (WSN). Latency aware and energy efficiency are two important parameters to evaluate the networks quality. In order to meet different performance requirements of the service, we classified the packets into high priority and low priority. We consider the latency and energy tradeoffs in WSN. The latency of the high priority packets is small but the network cost more energy. The latency of the packets of low priority packets is large but the network cost less energy. This problem is solved by the effect of transmitted redundant packet in the WSN. Assume the network has a cell-partitioned structure, and sensor moves according to one-step Markov path model with constant speed. Simulation shows that the scheduling algorithm with/without redundancy can realize the latency and energy tradeoffs in WSN.

Project II: Power-Aware Ad Hoc Wireless Networks

Ad hoc wireless networks involve peer-to-peer communication in a network with a dynamically changing topology. They do not rely on a preexisting fixed infrastructure, such as a wire line backbone network or a base station. They are self-organizing entities that are deployed on demand in support of various events including collaborative computing, multimedia classroom, disaster relief, search and rescue, and interactive mission planning. Scalability and energy-efficiency concerns suggest a hierarchical organization of ad hoc networks (AHN) systems with the lowest level in the hierarchy being a cluster.

Thus, it is important to design an optimal topology for self-organizing wireless AHN to maximally extend the above benefits. Of these, conserving battery power is the most significant because battery life is not expected to increase significantly in the coming years and AHNs are typically established in mission critical environments.

We propose to investigate some challenging topics in power-aware ad hoc wireless networks. The OPNET Modeler will be used to verify the new algorithms and protocols we will propose, and to compare with the existing schemes.

Project III: Asynchronous energy-efficient MAC protocols for wireless sensor networks

In this project, we hope to design asynchronous energy-efficient MAC protocols for wireless sensor networks. By applying free-running method and fuzzy logic rescheduling scheme, time synchronization which is necessary in existing energy-efficient MAC protocols is not required any more. Moreover, we are designing a traffic intensity and network density-based model to determine essential algorithm parameters. Through simulation, we hope to show that our algorithm can successfully acquire the optimum values of power on/off duration, interval of schedule broadcast, as well as super-time-slot size and order to ensure the average successful transmission rate, decrease the data packet average waiting time, and reduce the average energy consumption.

We use OPNET to do simulation to prove the performance of our algorithm.