SpectrumSharing_ThesisPPT_BSingh_AaltoUni_2014

Repeated Games for Inter-operatorSpectrum SharingBikramjit SinghSupervisor: Prof. Olav TirkkonenInstructor: PhD. Konstantinos Koufos

Department of Communications and Networking (COMNET)Aalto University, School of Electrical Engineering

Friday 24th January, 2014

Repeated Games for Inter-operator Spectrum SharingFriday 24th January, 2014

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Outline

I IntroductionI Background

I Related WorksI Related Standards

I Cooperative Spectrum SharingI Repeated Games based Spectrum Sharing

I Proposed Model using Virtual Spectrum PriceI Proposed Model using Mutual Gain/Loss History

I Numerical StudyI Conclusion and Future WorksI References


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IntroductionI 1000 times traffic, 50 billion devices by 2020 [1,2]

I 16 billion LTE RAT users in 2018 [3]

I Bandwidth requirements upto 1720 MHz for IMT by 2020 [4]

I

U.S. spectrum surplus/deficit per cell cite [5]


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Introduction

I

Summary frequency allocation 0.3-30 GHzI Spectrum utilization variations ranging from 15% to 85% [6]I Utilization of 0.5% in the 3-4 GHz and 0.3% in the 4-5 GHz

bands [7]I Less than 20% utilization in 3 GHz bands [8]I Problem is Spectrum Allocation not Physical Spectrum Scarcity


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Background

I Interference managementI How to tackle interference between peer-to-peer entities?

I UtilityI Represents the system’s performance level or QoSI A convex function

I Game theoryI To model interactions involving conflicting objectivesI Game G invloving P number of players, their startegy profile

set S and utility function U , represented as, G = 〈P,S, U〉


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Related WorksI Cooperative games

I Highest gainsI Signalling overheadsI Operators trust each otherI Exchange information can be falsified

I Repeated gamesI Operators can be hostileI Punishment mechanismI One-shot games

I Poor EquilibriaI Punishment too strict

I Infinite Repeated gamesI Power domainI Spectrum related work involves monetary transactions


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Related Standards

I IEEE 802.11 for Intra-cell/Inter-cell TransmissionI Tackles intra/inter-cell transmission problems

I IEEE 802.11h for Spectrum Management in 5 GHz BandI Only noisy 802.11h device adjusts its spectrum via DFS

I IEEE 802.16h for Improved Coexisting MechanismI Works in the time domain

I IEEE 802.22 for using White Spaces in the TV SpectrumI Intended for centralized inter-network resource sharing

However, Inter-operator spectrum sharing is a non-centralizedimplementation where all the operators participate and aim toresolve inter-operator spectrum needs in the frequency domain


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Cooperative Spectrum Sharing

I Motivation - P. Amin, O. Tirkkonen, T. Henttonen, andE. Pernila, "Dynamic frequency selection based on carrierpricing between cells," in Proc. IEEE VTC’13 Spring

I

System architecture


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Cooperative Spectrum Sharing

Cooperative decision mechanism for spectrum sharing

I Operator Oi adds unused carrier k and compares its utilitygain Gi,k with operator O−i ’s utility loss L−i,k

if Gi,k > L−i,k thendo START using carrier k

end ifI Operator Oi removes used carrier k and compares its

utility loss Li,k with operator O−i ’s utility gain G−i,kif Li,k < G−i,k then

do STOP using carrier kend if


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Repeated Games based Spectrum Sharing

I

System architectureI Game := Game(Utility, Decision, Check)I Spectrum usage favors

I Operator STARTs using the CC alongside opponentI Opponent STOPs using the CC if asked by operator


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Proposed Model using Virtual Spectrum Price

I Utility U, chosen as a function of cell throughput T andvirtual carrier price λ,

U = f (T )− λwhere, λ = p1(ep2K/K − 1), with p1 and p2 are pricingconstants, K and K are the numbers representing activeand full CC utilization

I Decision, to a new carrier allocation startegy s adopted byoperator Oi , the following utility conditions must satisfy,

Oi : Ui,s > Ui O−i : U−i,s > U−i

I Operators check the game by limiting spectrum usagefavors h against the maximal limit, surplus S,

Oi : h−i − hi ≤ S O−i : hi − h−i ≤ S


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Proposed Model using Mutual Gain/Loss History

I Utility U, chosen as a function of cell throughput T ,U = f (T )

I Decision, to a new carrier allocation startegy s adopted byoperator Oi , operator Oi compares immediate utility gainGi,s against expected loss Li,s, and operator O−i comparesimmediate utility loss L−i,s against expected gain Gi,saccordingly,

Oi : Gi,s > Li O−i : L−i,s < G−i

I Operators check the game by limiting spectrum usagefavors h against the maximal limit, surplus S,

Oi : h−i − hi ≤ S O−i : hi − h−i ≤ S


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Numerical Study

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User Rate (Mbps)

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Orthogonal, Op. AOrthogonal, Op. BFull Spread, Op. AFull Spread, Op. BCooperative, Op. ACooperative, Op. BProp., Op. A, S=2Prop., Op. B, S=2

Figure: Rate distribution for operator Oa, Na = 25 users and operatorOb, Nb = 5 users using various schemes in a high interferenceenvironment. The maximum number of outstanding favors, S = 2.


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Numerical Study

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User Rate (Mbps)

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OrthogonalFull SpreadCooperativeProp., S=2

Figure: Rate distribution for operator Oa with temporal load variations(for first half of simulations with Na = 25 users and the second halfwith Na = 5 users) using various schemes in a high interferenceenvironment. The maximum number of outstanding favors, S = 2.


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Numerical Study

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User Rate (Mbps)

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CooperativeProp., S=2Prop., S=4

Figure: Rate distribution for operator Oa, Na = 25 users using variousschemes in a high interference environment. The maximum numberof outstanding favors is varied and rate curves are analysed for,S = 2 and 4.


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ConclusionI Investigated the impact of noncooperative games between the

operators on spectrum sharing

I Properly modelled games provide a clear gain over full spreadand orthogonal spectrum sharing

I Gains are significant when the number of serving users by anoperator is relatively large

Future WorksI Cooperative schemes for intra-operator radio resource

management

I Using outstanding favors in the decision making process

I Load prediction


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References

[1] "Wake-up call: Industry collaboration needed to make beyond 4G networks carry1000 times more traffic by 2020," White Paper, Nokia Siemens Networks, Aug. 2011.[2] "More than 50 billion connected devices," White Paper, Ericsson, Feb. 2011.[3] "LTE release 12 - taking another step toward the networked society," White Paper,Ericsson, Jan. 2013.[4] "Estimated spectrum bandwidth requirements for the future development ofIMT-2000 and IMT-Advanced," International Telecommunication Union ITU, Tech. Rep.M.2078.[5] Federal Communications Commission FCC, Tech. Rep., Feb. 2012.[6] "First report and order in the matter of revision of part 15 of the commission’s rulesregarding ultra wideband transmission systems," Federal CommunicationsCommission FCC, FCC 02-48 ET Docket 98-153, Feb. 2002.[7] D. Cabric, S. M. Mishra, and R. W. Brodersen, "Implementation issues in spectrumsensing for cognitive radios," in Proc. Asilomar Conference on Signals, Systems andComputers (ASILOMAR’04), Nov. 2004, pp. 772-776.[8] V. Valenta, R. Maršálek, G. Baudoin, M. Villegas, M. Suarez, and F. Robert, "Surveyon spectrum utilization in europe: Measurements, analyses and observations," in Proc.IEEE International Conference on Cognitive Radio Oriented Wireless Networks(CROWNCOM’10), Jun. 2010, pp. 1-5.


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Thank You

Science

SpectrumSharing_ThesisPPT_BSingh_AaltoUni_2014