Co-primary inter-operator spectrum sharing over a limited spectrum pool using repeated games

Abstract

Abstract-We consider two small cell operators deployed in the same geographical area, sharing spectrum resources from a common pool. A method is investigated to coordinate the utilization of the spectrum pool without monetary transactions and without revealing operator-specific information to other parties. For this, we construct a protocol based on asking and receiving spectrum usage favors by the operators, and keeping a book of the favors. A spectrum usage favor is exchanged between the operators if one is asking for a permission to use some of the resources from the pool on an exclusive basis, and the other is willing to accept that. As a result, the proposed method does not force an operator to take action. An operator with a high load may take spectrum usage favors from an operator that has few users to serve, and it is likely to return these favors in the future to show a cooperative spirit and maintain reciprocity. We formulate the interactions between the operators as a repeated game and determine rules to decide whether to ask or grant a favor at each stage game. We illustrate that under frequent network load variations, which are expected to be prominent in small cell deployments, both operators can attain higher user rates as compared to the case of no coordination of the resource utilization.Keywords-Co-primary spectrum sharing, repeated games, spectrum pooling. I. INTRODUCTIONIn the state-of-art mobile communication systems, a network operator possesses a spectrum license that provides exclusive transmission rights for a particular range of radio frequencies. Spectrum assignment based on dedicated licenses resolves the issues related to inter-operator interference but it also results in low spectrum utilization efficiency. Inter-operator spectrum sharing is envisioned as one of the viable approaches to achieve higher operational bandwidth efficiency and meet the increasing mobile data traffic demand in a timely manner [1].In the limited spectrum pool (LSP) scenario, a limited number of operators share a common resource pool by relying on more flexible and adaptive prioritization policies than is currently possible with dedicated licenses [2]. Cognitive radio technologies are effective measures to resolve the sharing conflicts over the LSP under vertical spectrum sharing [3], where the lessor (owner) operator has higher legacy rights over the spectrum than the lessee operator. On the other hand, the co-primary or horizontal spectrum sharing scheme conceptualizes the case where authorized operators possess equal ownership on the spectrum being adopted [4]. However, a priori agreements should be made on the spectrum usage with regard to the long term share of an individual operator.The multilateral use of shared resources in the LSP can, for instance, be achieved with channel allocation schemes originally developed for single-operator systems. These schemes

Coexistence of Age and Throughput Optimizing Networks: A Game Theoretic Approach

“…Works such as [22]- [24] have employed repeated games in the context of coexistence. Since repeated games might foster cooperation, authors in [22] study a punishment-based repeated game to model cooperation between multiple networks in an unlicensed band and illustrate that under certain conditions selfish behavior incur negligible losses and whether the systems cooperate or not does not have much influence on the performance.…”

“…where, a n−1 , is the action profile observed by the networks in stage (n−1) and R n corresponds to the signal from the coordination device P R . As shown in (24), if a n−1 ∈ {(T , I),(I, T )} networks play (φ * A , φ * T ). In a nutshell, cooperation is sustained as long as the players comply to the recommendation of the coordination device P R .…”

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

“…In the case that national roaming is not a desirable solution for the competitive MNOs, other types of sharing such as mutual renting and LSA-like approaches can prove beneficial. In this case, the MNOs can leverage their own existing infrastructure Mutual Renting (V-C-2-a) [115], [126][127] Spectrum Pooling (V-C-2-b) [80], [82], [84][85], [97] Inter-operator Spectrum and RAN Sharing (V-C-1)…”

“…Database driven (e.g., geo-location database) [37], [79] + Provides accurate information regarding spectrum availability across the network + Reliable interference protection for sharing players + Can be an unbiased entity for fair spectrum allocation among sharing players -T oo complex for real-time spectrum opportunity detection -Requires additional infrastructure for deployment such as backhaul -Requires a third party to manage the sharing procedure -Imposes excess signalling overhead to the network/participating systems -Vulnerable to jamming attacks Spectrum broker/ Super resource scheduler [83], [84] Distributed Spectrum sensing (e.g., energy detection) [61], [37] , [33], + Is capable for on-demand and real-time spectrum opportunity detection + No additional infrastructure is required + Only target UE is involved to perform sensing, thus, lower signalling is imposed to the network -Is vulnerable to some issues such hidden node, false alarm and detection -Is not reliable for QoS sensitive services when sensing is performed by UE Coordinated Beamforming [85], [86] + Simultaneous utilisation of spectrum by multiple service providers + Increased spectrum utilisation efficiency -Requires CSI sharing between sharing players -Requires interface (such as backhaul, X2, etc.) between sharing players Game-T heory based coordination [87], [88], [89] + Low to no, information sharing between sharing players during sharing procedure + Low to no overhead is imposed to the network -Implementation complexities -Low fairness guarantees between sharing players…”

“…Such issues are likely to be determined by the NRAs and are variable in each country. More information on economic and business aspect analysis can be found in [54], [84], [101], and [103].…”