Market-Equilibrium, Competitive, and
Cooperative Pricing for Spectrum Sharing in Cognitive
Radio Networks: Analysis and Comparison
Advisor ：Wei-Yeh Chen
Student ：楊


于
世
Reference
D. Niyato, E. Hossain, “Market-Equilibrium, Competitive, and
Cooperative Pricing for Spectrum Sharing in Cognitive Radio
Networks: Analysis and Comparison,” IEEE Wireless
Commun., vol. 7 , issue: 11 , part 1 , pp. 4273 - 4283 , Nov.
2008.
1
Outline

Introduction

Cognitive wireless network model

Distributed implementation of the pricing models

Numerical Results

Conclusion
2
Introduction(1/2)

In a cognitive radio network, frequency spectrum can be
shared between primary users and secondary users, where the
secondary users pay the primary users for radio resource usage.

In a cognitive radio network, pricing model for spectrum
sharing depends on the objective of spectrum trading, and
therefore, the behaviors of spectrum sellers and spectrum
buyers.
3
Introduction(2/2)

In this paper, we investigate three different pricing models,
namely, market-equilibrium, competitive, and cooperative
pricing models for spectrum trading in a cognitive radio
environment.

In these pricing models, the primary service providers have
different behaviors to achieve different objectives of spectrum
trading.
4
Cognitive wireless network model

Primary and Secondary Services

Pricing Models
5
Primary and Secondary Services

When a primary service is not fully utilizing its spectrum, it
can sell portions of the available spectrum to the secondary
users who are willing to buy the spectrum.

In this way, a spectrum trading market is established(建立)
where a seller and a buyer correspond(相當) to the primary
and secondary services, respectively.
6
System model for spectrum sharing.
7
Pricing Models

Market-Equilibrium-Based Pricing Model

Competitive Pricing

Cooperative Pricing
8
Market-Equilibrium-Based Pricing Model

In this spectrum trading, market-equilibrium price denotes
the price for which spectrum supplied by the primary service is
equal to the spectrum demand from the secondary service.

This market-equilibrium price ensures(保証) that there is no
excess supply in the market and spectrum supply meets all
spectrum demand.
9
Competitive Pricing

In the competitive pricing model, it is assumed that a primary
service is aware of the existence of other primary services and
all of the primary services compete with each other to achieve
the highest individual profit.

The spectrum prices offered by other primary services, one
primary service chooses the price for its own spectrum so that
its individual profit is maximized.
10
Cooperative Pricing

In the cooperative pricing model, it is assumed that all of the
primary services know each other and they fully cooperate to
obtain the highest total profit by selling spectrum to the
secondary service.
11
Distributed implementation of the pricing
models

In a practical(實際的) cognitive radio environment, a primary
service may not have the complete network information.

In all of the pricing models, a primary service must learn the
behavior of other entities from the history, and a distributed
price adjustment algorithm is required which would gradually
reach the solution.
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P:價格
D:需求
S:供應
α: 學習率
t: 時間
Market-equilibrium pricing model
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Competitive pricing model
14
Cooperative pricing model
15
Numerical Results(1/4)

We observe that for a given vector of prices, a primary service
sharing spectrum with secondary service can gain higher profit
than that which does not share.

If the price is too low, spectrum demand from secondary
service becomes high, and the performance of the primary
service degrades.

When the price increases, the demand decreases.
16
Total profit and solutions of market-equilibrium, competitive, and
cooperative pricing models.
17
Numerical Results(2/4)

Spectrum supply depends largely on the number of primary
users and their bandwidth requirements.

Specifically, when the number of ongoing primary users and/or
their bandwidth requirements increase, spectrum supply
decreases and vice versa.
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Demand and supply functions.
19
Numerical Results(3/4)

The three different pricing models, when γ1 increases, the
corresponding spectrum demand becomes larger, and
therefore, primary service one can increase its offered price to
gain higher profit.

However, for primary service two, since the demand from the
secondary service decreases, spectrum price, and
consequently(因此), profit due to spectrum trading decreases.
20
Price adaptation under different channel qualities.
21
Numerical Results(4/4)

Due to the nature of the demand function, for market
equilibrium pricing, when the number of primary services
increases, spectrum demand will increase with a corresponding
increase in spectrum price.

However, for competitive pricing, an increase in the number of
primary services results in a higher degree of competition, and
consequently, spectrum price decreases.
22
Price adaptation under different number of primary services.
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Conclusion

之前想到說可以做交易機制中的拍賣，不過並沒有想到可
以比較的對象，不過這篇讓我覺得其實可以讓拍賣機制與
競爭機制做一個比較，因為拍賣機制我覺得也類似一種競
爭機制，所以，想比較它們之間對效能上的差別。
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