Sensor Network Optimizations Using Software Defined Radio Techniques

Medium Access Control (MAC) protocols for low duty cycle wireless sensor networks (WSNs) are characteristic of tight state control of the radio transceiver and extensive use of link quality information about a node's neighborhood, driven by the demand of bandwidth and energy efficiency. Determination of optimal MAC protocol mechanisms and parameters is, however, often a slow and difficult process, because the constraints of the underlying radio hardware put a limit on the ranges of parameters and introduce complicated trade-offs among them. Such complexities can only be resolved by empirical studies. But a moderate extension or modification of the MAC protocol will trigger a lengthy process of function verification and parameter optimization.

Software Defined Radio can speed up MAC protocol optimization by offering a richer set of radio control functions than single chip RFIC radios. Another benefit of SDR is that digital baseband signal processing can be done by high level programming languages, tailored to the user's need. The open source GNU Radio library, combined with its USRP radio frontend, is a powerful research and development tool that we intend to build MAC protocol prototypes for WSNs.

The thesis project involves the following tasks:
- Optimize a number of link quality estimation algorithms and verify them in an indoor sensor network testbed;
- Derive a timing specification of GNU Radio and USRP empirically;
- Based on the knowledge obtained, design a latency/energy optimized MAC for Contiki OS. An existing MAC for Contiki will be used as reference;
- Implement and evaluate the MAC using GNU Radio and USRP.

The student needs to put theory into practice. A motivation to obtain insights into fundamental research problems by conducting controlled experiments is key to a successful thesis.

The candidate is required to:
- have a background in principles of computer architectures and operating systems;
- have a background in principles of computer networks and wireless communication;
- have a basic understanding of digital radio architecture;
- be able to implement mathematic algorithms and state machines in C/C++;
- feel comfortable with Linux and GNU tool chain.

The successful completion of the project will add further strength to our group's competence in sensor networking research. Important results gained from the thesis will be reported as an academic publication.

If you write an application, please provide us with a CV, your courses and grades. In addition, we appreciate an article, paper, thesis or other relevant documents you have written in your education in order to judge your ability to express yourself in English. Please send your application to [email protected]