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Equilibrium and Disequilibrium Pricing forSpectrum Trading in Cognitive Radio: A

Control-Theoretic Approach

Advisor Advisor ： Wei-Yeh Chen

StudentStudent ：楊　 于　 世 Reference D. Niyato , E. Hossain, “Equilibrium and Disequilibrium Prici

ng for Spectrum Trading in Cognitive Radio: A Control- Theoretic Approach,” in GLOBECOM Washington DC, pp. 4852 - 4856 , Nov. 2007 .

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Outline

Introduction

System model

Spectrum supply and demand functions

Pricing for spectrum trading

Performance diagram

Conclusion

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Introduction(1/2)

Spectrum trading is a concept used to describe the economics of dynamic spectrum sharing in cognitive radio networks.

In this paper, we model and analyze spectrum trading in a cognitive radio environment, where the primary service

(i.e., spectrum owner) shares the spectrum with the secondary

services (i.e., spectrum buyers).

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Introduction(2/2)

In spectrum trading, an equilibrium price is required to satisfy all of the entities in the market.

We consider the disequilibrium case where the spectrum price does not conform(遵守 ) to the market equilibrium.

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System model

Primary and Secondary Services

Spectrum Trading Model

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Primary and Secondary Services

We consider a wireless system with a single primary service operating on multiple frequency spectrum.

The primary service serves NP,i local connections using the frequency spectrum Fi which is of size Wi.

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System model for spectrum sharing.

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Spectrum Trading Model

The price of spectrum in each market depends on the spectrum supply from the primary service and the demand from the secondary service.

The primary service/user may not be fully utilized, and the primary service may want to exploit(利用 ) this spectrum underutilization(未充分使用 ) and sell the spectrum opportunities to secondary service(s).

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Spectrum supply and demand functions

Primary Service ： Profit and Spectrum Supply

Secondary Service ： Utility and Spectrum Demand

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Pricing for spectrum trading

Equilibrium Pricing

Disequilibrium Pricing

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Equilibrium Pricing

In this model, the price is used to determine spectrum supply and demand for the primary and the secondary services, respectively.

The difference between spectrum demand and supply is then fed back to adjust the price.

The price of one frequency band affects the demand for another frequency band.

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Block diagram of the equilibrium pricing control system.

P： Price S： Supply

D： Demand λ： Control parameter

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Step response of equilibrium prices.

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Disequilibrium Pricing

The price of spectrum F2 is set to a value which does not conform to the equilibrium.

In this case, the excess demand for F2 is aggregated(聚集 ) with that of spectrum F1.

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Block diagram of the disequilibrium pricing control system.

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Step response of equilibrium prices under disequilibrium condition.

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Conclusion

頻譜交易中，平衡與非平衡的概念，在這些機制中，加入控制參數後，去調整價格，讓市場能達到平衡，使主要頻譜的擁有者能得到最佳的利益，次要使用者得到最佳的頻譜服務品質。