Spectrum is a valuable, scarce and finite natural resource that is needed for many different applications, so efficient use of the scarce radio spectrum is important for accommodating the rapid growth of wireless communications. Spectrum auctions are one of the best-known market-based solutions to improve the efficiency of spectrum use. However, Spectrum auctions are fundamentally differen...

We formulate and study a multi-user multi-armed bandit (MAB) problem that exploits the temporal-spatial opportunistic spectrum access (OSA) of primary user (PU) channels so that secondary users (SUs) who do not interfere with each other can make use of the same PU channel. We first propose a centralized channel allocation policy that has logarithmic regret, but requires a central processor to s...

We design truthful double spectrum auctions where multiple parties can trade spectrum based on their individual needs. Open, market-based spectrum trading motivates existing spectrum owners (as sellers) to lease their selected idle spectrum to new spectrum users, and provides new users (as buyers) the spectrum they desperately need. The most significant challenge is how to make the auction econ...

This paper presents a simulation based energy consumption analysis of a heterogeneous network (HetNet) consisting of Long Term Evolution (LTE) macro-cells and LTE femto-cells. Two potential areas of energy savings are evaluated, namely, sleep modes and spectrum assignment. Sleep modes are demonstrated with practical component level power models, resulting considerable energy savings. Three spec...

Is it really true that simulation models and simulation software should always be regarded as candidates for reuse, or is it better to be selective? What are the obstacles to simulation software and model reuse? Can these be surmounted and, if so, at what cost? There is a range of levels at which simulation software may be reused, a range of costs to be borne and range of benefits that may be a...

Cognitive radio is a means to solve the spectrum scarcity problem by allowing secondary spectrum users to share channels with the primary spectrum users in an opportunistic fashion. However, cognitive radio requires high costs in terms of spectrum sensing and monitoring system complexities as well as potential interference issues to the primary spectrum users. In this paper, we propose a spatia...

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In this paper, unlicensed reuse of licensed spectrum is discussed from the regulatory point of view. This issue concerns the regulator by the possibility of interference to existing services, and also the increase of spectrum efficiency. Ultrawideband (UWB) technology is an interesting subject for this matter and here, the topic of the paper is discussed through a case study of UWB.