Martino M. Freda

Mechanisms for LTE coexistence in TV white space

This paper presents a high level description of an LTE system operating in license exempt bands. Since wireless networks potentially using different air interfaces may operate in these bands, coexistence is a challenge that needs to be addressed. This paper focuses on non-coordinated mechanisms for secondary users coexistence, and introduces a coexistence gap based method for LTE to dynamically share the spectrum with other secondary users. A simulation based analysis of the coexistence gap method is presented, and the results are compared with an energy based sensing channel access method.

On a new incentive and market based framework for multi-tier shared spectrum access systems

The popularity of the smartphone and the resulting increase in the volume of wireless data traffic has created a large gap between bandwidth supply and demand. An attractive and less expensive solution to re-farming of spectrum is to maximize the use of under-utilized bands through spectrum sharing. Recent efforts in this area, that propose operation of wireless systems in shared spectrum, address the main challenge of how shared spectrum access systems can efficiently share and utilize spectrum resources. In this paper, we focus on the framework for multi-tier shared spectrum operation in wireless networks, where multiple entities - the Shared Spectrum Managers (SSMs) - dynamically acquire, manage and sell shared spectrum. We derive an auction based spectrum resource assignment algorithm which maximizes the overall system efficiency and provides incentives to the incumbents to make spectrum available for sharing. We demonstrate that the algorithm can be implemented in practice through messaging in which the SSM dynamically negotiates spectrum bidding and asking prices with the shared spectrum users. Simulations are performed under different scenarios and assumptions both to verify that the algorithm achieves the maximum utility value for shared spectrum systems, and to compare the outcome behavior under each scenario. Based on the observations, potential regulations that would need to be put in place in each scenario are discussed, and a set of future development areas are identified based on these observations.