The radio spectrum is becoming an increasingly valuable natural resource nowadays, while it has been shown that much of the spectrum is underutilized in existing licensed bands. To enhance spectrum utilization, dynamic spectrum access (DSA) has been envisioned as a set of promising new spectrum management paradigms, such as spectrum trading/auction and opportunistic spectrum access. While DSA and programmable cognitive radios enable a much higher flexibility of spectrum access, due to the openness of wireless medium, it is also susceptible to various forms of misuse or abuse. For example, unauthorized transmissions without a valid license, or secondary transmissions that intentionally disobey the interference constraints set by the primary users (radios). The misusers will not only gain higher throughput for themselves, but also harm the efficiency of spectrum access operations of normal users (radios). Therefore, enforcing spectrum access rules or etiquettes is crucial to ensuring the ultimate success of the DSA paradigm.

This project develops a framework for etiquette and rule enforcing in dynamic spectrum sharing environments. The main idea of the proposed research is to engage community users (radios) to detect misuse, and identify and punish unruly devices. By crowdsourcing the tasks of monitoring neighborhood radio access behaviors to many cognitive radio devices, multiple benefits can be gained: 1) the potentially large number of participating devices can result in much larger detection coverage and accuracy; 2) no pervasive dedicated trusted infrastructure or hardware is needed; and 3) the fact that every device could possibly be a monitoring device leads to a much stronger deterrence to misbehaviors. The interdisciplinary research plan consists of four major components: 1) an optimized crowdsourced passive radio traffic monitoring framework to detect access misbehavior in the vast DSA spectrum; 2) techniques to identify misbehaving cognitive radio devices using physical layer identification, even when the signal waveform can be adaptively modified; 3) techniques for immediate punishment of spectrum misuse through adaptive friendly jamming which exploits multi-functional re-configurable antennas; and 4) incentive mechanism design via auctions to ensure user participation in each task of crowdsourced etiquette enforcement. The success of this project will benefit multiple current and future application domains deploying DSA, especially those that require critical information protection, such as healthcare, transportation, energy, public services, emergency, and military services.

The outcomes have been made available to research community through high quality journal articles and conference presentations. The research has resulted in 6 journal papers and 13 conference papers. More specifically, two algorithms or frameworks have been designed to monitor the spectrum usage, 14 incentive mechanisms or frameworks have been designed to provide incentives to crowdsourcing participants while considering privacy, security, and quality, 2 algorithms have been designed to allocate the crowdsourcing tasks to participants while considering energy efficiency.

The proposed research activities have complemented and enriched the growing curriculum on game theory and optimization at Colorado School of Mines and the University of Arizona through course development and special topic seminars.

Highly skilled personnel in related areas have been trained in carrying out the proposed research tasks. Special efforts have been made to engage minority and underrepresented groups. Two female Ph.D. students, Ming Li and Yuhui Zhang have been involved in this project at Colorado School of Mines. A hispanic undergraduate student also gained experience via participation of this project. Therefore, this project also played a role in the integration of under-represented groups to the scientific community.

Last Modified: 03/30/2019
Modified by: Dejun Yang