Spectrum Leasing in Cognitive Radio Networks: A Survey

Abstract

Cognitive Radio (CR) is a dynamic spectrum access approach, in which unlicensed users (or secondary users, SUs) exploit the underutilized channels (or white spaces) owned by the licensed users (or primary users, PUs). Traditionally, SUs are oblivious to PUs, and therefore the acquisition of white spaces is not guaranteed. Hence, a SU must vacate its channel whenever a PU reappears on it in an unpredictable manner, which may affect the SUs' network performance. Spectrum leasing has been proposed to tackle the aforementioned problem through negotiation between the PU and SU networks, which allows the SUs to acquire white spaces for a guaranteed period of time. Through spectrum leasing, the PUs and SUs enhance their network performances, and additionally PUs maximize their respective monetary gains.

Licensed Spectrum Sharing Schemes for Mobile Operators: A Survey and Outlook

“…The TVWSs and Digital Video Broadcast (DVB) in 700MHz bands are the most common candidates to be used under this access method with rather low license fees [29]. Spectrum leasing policies have been applied to offer a more robust (in terms of access guarantees) form of OSA/DSA schemes in licensed bands in CRNs [66], where for example, the white spaces are leased to SUs subject to pre-negotiation with PUs. The PUs determine the cost of white spaces based on parameters such as; channel access time, type of SUs, etc., to increase their monetary gain, however, the PUs need to perform continuous monitoring of SUs' activities.…”

“…In the case of spectrum sharing, the license fee will be lower than the cost of an auction-based spectrum (conventional trend for spectrum allocation) or via trading (spectrum is assigned to a new user who needs it) [101]. There have been proposed varieties of trading schemes for the pricing such as channel-quality based price, game-theoretic based (such as NE), and also demand-supply model in which the shared bands are assigned to the highest bidders [102] and spectrum leasing [66]. However, more reasonable pricing policies are required to incentive sharing players to participate in spectrum sharing.…”

Efficient spectrum leasing in cognitive radio networks: Disjoint secondary user selection and protocol selective relaying

“…The main characteristic of the overlay approaches, which this paper also belongs to, is that the primary network is fully aware of the presence of the secondary network's activity. Thus, the two networks probably are willing to form a partnership for mutual benefits, and this leads to performance improvement for the primary network as well as dedicated channel access for the secondary network .…”

“…The main characteristic of the overlay approaches, which this paper also belongs to, is that the primary network is fully aware of the presence of the secondary network's activity. Thus, the two networks probably are willing to form a partnership for mutual benefits, and this leads to performance improvement for the primary network as well as dedicated channel access for the secondary network [7]. Spectrum leasing is known as an overlay-based spectrum sharing technique where the primary network leases a part of its own spectrum and receives benefit in the form of network performance enhancement through packet forwarding by secondary users, and the secondary network uses the released spectrum to transmit in.…”

Spectrum Leasing in Cognitive Radio Networks: A Matching Theory Approach

“…The specific technology implies the existence of two different types of users: the licensed users (Primary Users-PUs) and the unlicensed users (Secondary Users-SUs) who are allowed to access the licensed spectrum under specific conditions depending on the dynamic access technique that is employed (overlay, underlay or interweave). However, the fact that, in most cases, the SUs are obligated to restrict their transmission either because of the unpredictable PUs' transmissions or due to the necessary sensing periods, has led to the concept of spectrum leasing [2]. In contrast with the commons model approach, where the PUs are oblivious to the presence of SUs, in spectrum leasing (or property rights model), it is considered that the PUs own the spectral resources and they can cooperate with the SUs so as to ameliorate their performance [3].…”