A Truthful Online Incentive Mechanism for Nondeterministic Spectrum Allocation

Dynamic spectrum access (DSA) is a promising platform to solve the problem of spectrum shortage for which the most challenging issue is spectrum allocation under uncertain availability information, which is referred as a nondeterministic spectrum allocation problem. The nature of such a problem is due to inaccurate spectrum sensing results, which are induced by that power or energy based sensing can be greatly impacted by thermal and environmental noise. For spectrum allocation, auction-based mechanisms have been extensively studied because of channel allocation efficiency, and its potential to achieve bidding truthfulness for secondary uses (SUs). However, most existing spectrum auction mechanisms focus on realizing the truthfulness under certain spectrum availability information. In this paper, we propose FORTUNE, the first truthful online auction mechanism for nondeterministic spectrum allocation by considering uncertain spectrum availability and dynamic spectrum requests. Specifically, we take limited information to compute expected income and losses when interference between primary users (PUs) and SUs occurs, and present a virtual request method for changing of spectrum's actual state. Thorough theoretical analysis proves the truthfulness of FORTUNE. Furthermore, given a sample set with 5%-30% noise in spectrum sensing, FORTUNE achieves not only truthfulness, but also up to 50% higher channel utilization than existing spectrum auction mechanisms.

I. Introduction

Spectrum is a scarce and non-renewable resource, therefore with the increasing demand for wireless communications, the spectrum shortage problem becomes more and more serious. With the potential of increasing spectrum utilization, dynamic spectrum access (DSA) is regarded as a promising platform to solve the spectrum shortage problem. In DSA, wireless devices (i.e., secondary users, SUs) without interference are allowed to dynamically access unoccupied channels, which belongs to primary license holder(i.e., primary users, PUs). Most existing spectrum allocation mechanisms (e.g., [2]–[6]) in DSA assume that an auctioneer has complete knowledge about spectrum state information (e.g., spectrum is available/busy for use by SUs deterministically). However, the complete knowledge about the spectrum state information cannot be obtained all the time. Spectrum allocation problem under uncertain spectrum availability should be discussed, which refers to nondeterministic spectrum allocation [1].