The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Kang G. Shin - One of the best experts on this subject based on the ideXlab platform.
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Hierarchical Market Competition in a Duopoly Super Wi-Fi Spectrum Market
IEEE Journal on Selected Areas in Communications, 2013Co-Authors: Jaehyuk Choi, Kang G. ShinAbstract:Super Wi-Fi refers to Wi-Fi-like Internet access via spectrum white spaces (WS), which is expected to enhance today's Wi-Fi thanks to the superior propagation characteristics of the WS compared to ISM/UNII bands. A Super Wi-Fi wireless service provider (WSP) dynamically leases and opportunistically utilizes a licensed band while it is temporarily unoccupied by its (licensed) primary users (PUs). The PUs' spectrum usage pattern presents time-varying spectrum availability, thus necessitating eviction of in-service customers upon return of PUs where the evicted customers are compensated with partial reimbursement of their service charge. This paper investigates the dynamics of a duopoly Super Wi-Fi market where two co-located WSPs compete for leasing better quality channels and for setting competitive service price to entice more customers. The channel quality is measured by the PUs' utilization factor (smaller the better). Since higher quality channels possess more WS incurring larger channel leasing cost, a WSP should strike a balance between channel quality and service tariff in maximizing its profit. The market competition is modeled as hierarchical noncooperative price- and quality-games, and their Nash Equilibria (NE) are derived. In addition, we investigate the impact of differentiated reimbursement rates and limited channel availability. Finally, we demonstrate the tradeoffs among leasing cost, customer arrival rate, and channel characteristics via numerical analyses.
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Admission and Eviction Control of Cognitive Radio Users at Wi-Fi 2.0 Hotspots
IEEE Transactions on Mobile Computing, 2012Co-Authors: Kang G. ShinAbstract:Cognitive radio (CR)-based Wi-Fi 2.0 hotspots are introduced as an attractive application of dynamic spectrum access (DSA), at which a wireless service provider (WSP) leases licensed channels via secondary market and offers Internet access to CR-enabled customers by opportunistically utilizing the leased spectrum. The CR users access the channels only when they are temporarily unoccupied by their legacy users, and pay a usage charge according to the WSP's pricing policy. In this paper, we study the profit maximization problem of a WSP by deriving the (sub)optimal control of admission (at CR user arrivals) and eviction (upon return of the legacy users) of CR users. We formulate the problem as a semi-Markov decision process (SMDP) with two quality-of-service (QoS) constraints on arrival-blocking and service-dropping probabilities, which is solved by the linear programming techniques. Using an extensive numerical analysis, we show that the derived policy achieves up to 22.5-44 percent more profit than simple complete-sharing algorithms in the tested scenarios. In addition, we evaluate the impact of the number of leased channels and pricing on the achieved profit, and study the tradeoffs between the two QoS constraints.
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Wi-Fi 2.0: Price and quality competitions of duopoly cognitive radio wireless service providers with time-varying spectrum availability
2011 Proceedings IEEE INFOCOM, 2011Co-Authors: Jaehyuk Choi, Kang G. ShinAbstract:The whitespaces (WS) in the legacy spectrum provide new opportunities for the future Wi-Fi-like Internet access, often called Wi-Fi 2.0, since service quality can be greatly enhanced thanks to the better propagation characteristics of the WS than the ISM bands. In the Wi-Fi 2.0 networks, each wireless service provider (WSP) temporarily leases a licensed spectrum band from the licensees and opportunistically utilizes it during the absence of the legacy users. The WSPs in Wi-Fi 2.0 thus face unique challenges since spectrum availability of the leased channel is time-varying due to the ON/OFF spectrum usage patterns of the legacy users, which necessitates the eviction control of in-service customers at the return of legacy users. As a result, to maximize its profit, a WSP should consider both channel leasing and eviction costs to optimally determine a spectrum band to lease and a service tariff. In this paper, we consider a duopoly Wi-Fi 2.0 market where two co-located WSPs compete for the spectrum and customers. The competition between the WSPs is analyzed using game theory to derive the Nash Equilibria (NE) of the price (of the service tariffs) and the quality (of the leased channel, in terms of channel utilization) competitions. The NE existence condition and market entry barriers are also derived. Via an extensive numerical analysis, we show the tradeoffs between leasing/eviction cost, customer arrivals, and channel usage patterns by the legacy users.
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INFOCOM - Wi-Fi 2.0: Price and quality competitions of duopoly cognitive radio wireless service providers with time-varying spectrum availability
2011 Proceedings IEEE INFOCOM, 2011Co-Authors: Jaehyuk Choi, Kang G. ShinAbstract:The whitespaces (WS) in the legacy spectrum provide new opportunities for the future Wi-Fi-like Internet access, often called Wi-Fi 2.0, since service quality can be greatly enhanced thanks to the better propagation characteristics of the WS than the ISM bands. In the Wi-Fi 2.0 networks, each wireless service provider (WSP) temporarily leases a licensed spectrum band from the licensees and opportunistically utilizes it during the absence of the legacy users. The WSPs in Wi-Fi 2.0 thus face unique challenges since spectrum availability of the leased channel is time-varying due to the ON/OFF spectrum usage patterns of the legacy users, which necessitates the eviction control of in-service customers at the return of legacy users. As a result, to maximize its profit, a WSP should consider both channel leasing and eviction costs to optimally determine a spectrum band to lease and a service tariff. In this paper, we consider a duopoly Wi-Fi 2.0 market where two co-located WSPs compete for the spectrum and customers. The competition between the WSPs is analyzed using game theory to derive the Nash Equilibria (NE) of the price (of the service tariffs) and the quality (of the leased channel, in terms of channel utilization) competitions. The NE existence condition and market entry barriers are also derived. Via an extensive numerical analysis, we show the tradeoffs between leasing/eviction cost, customer arrivals, and channel usage patterns by the legacy users.
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Understanding Wi-Fi 2.0: from the economical perspective of wireless service providers [Dynamic Spectrum Management]
IEEE Wireless Communications, 2010Co-Authors: Kang G. ShinAbstract:Wi-Fi 2.0 refers to Wi-Fi-like Internet access operating on whitespaces in the licensed spectrum using cognitive radio technology. Wi-Fi 2.0 is expected to provide better performance and larger coverage than today's Wi-Fi, thanks to the good propagation characteristics of the legacy spectrum such as TV bands. Wi-Fi 2.0 is modeled as a network consisting of an access point (called CR hotspot) and end-user terminals (CR devices) operated by a CR wireless service provider. In this article we focus on the economical perspective of Wi-Fi 2.0 and discuss various aspects in profit management of Wi-Fi 2.0 WSPs. In particular, we consider profit-maximizing optimal strategies in terms of customer admission/eviction control and inter-WSP market competition. We first show that Wi-Fi 2.0 operates on time-varying spectrum availability due to the ON-OFF channel usage of legacy users, and advocate the necessity of customer eviction control upon appearance of legacy users. We also identify two types of WSP-WSP market competition in leasing the limited spectrum resources from the licensees and in enticing end customers with a competitive price. Then we enumerate the key factors affecting the profit of collocated WSPs, such as channel leasing cost, service tariff, QoS provisioning, and coexistence with legacy services. By examining Wi-Fi 2.0 from an economic point of view, we show its commercial value in developing next-generation CR applications that benefit both legacy and CR users.
Jaehyuk Choi - One of the best experts on this subject based on the ideXlab platform.
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Hierarchical Market Competition in a Duopoly Super Wi-Fi Spectrum Market
IEEE Journal on Selected Areas in Communications, 2013Co-Authors: Jaehyuk Choi, Kang G. ShinAbstract:Super Wi-Fi refers to Wi-Fi-like Internet access via spectrum white spaces (WS), which is expected to enhance today's Wi-Fi thanks to the superior propagation characteristics of the WS compared to ISM/UNII bands. A Super Wi-Fi wireless service provider (WSP) dynamically leases and opportunistically utilizes a licensed band while it is temporarily unoccupied by its (licensed) primary users (PUs). The PUs' spectrum usage pattern presents time-varying spectrum availability, thus necessitating eviction of in-service customers upon return of PUs where the evicted customers are compensated with partial reimbursement of their service charge. This paper investigates the dynamics of a duopoly Super Wi-Fi market where two co-located WSPs compete for leasing better quality channels and for setting competitive service price to entice more customers. The channel quality is measured by the PUs' utilization factor (smaller the better). Since higher quality channels possess more WS incurring larger channel leasing cost, a WSP should strike a balance between channel quality and service tariff in maximizing its profit. The market competition is modeled as hierarchical noncooperative price- and quality-games, and their Nash Equilibria (NE) are derived. In addition, we investigate the impact of differentiated reimbursement rates and limited channel availability. Finally, we demonstrate the tradeoffs among leasing cost, customer arrival rate, and channel characteristics via numerical analyses.
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Wi-Fi 2.0: Price and quality competitions of duopoly cognitive radio wireless service providers with time-varying spectrum availability
2011 Proceedings IEEE INFOCOM, 2011Co-Authors: Jaehyuk Choi, Kang G. ShinAbstract:The whitespaces (WS) in the legacy spectrum provide new opportunities for the future Wi-Fi-like Internet access, often called Wi-Fi 2.0, since service quality can be greatly enhanced thanks to the better propagation characteristics of the WS than the ISM bands. In the Wi-Fi 2.0 networks, each wireless service provider (WSP) temporarily leases a licensed spectrum band from the licensees and opportunistically utilizes it during the absence of the legacy users. The WSPs in Wi-Fi 2.0 thus face unique challenges since spectrum availability of the leased channel is time-varying due to the ON/OFF spectrum usage patterns of the legacy users, which necessitates the eviction control of in-service customers at the return of legacy users. As a result, to maximize its profit, a WSP should consider both channel leasing and eviction costs to optimally determine a spectrum band to lease and a service tariff. In this paper, we consider a duopoly Wi-Fi 2.0 market where two co-located WSPs compete for the spectrum and customers. The competition between the WSPs is analyzed using game theory to derive the Nash Equilibria (NE) of the price (of the service tariffs) and the quality (of the leased channel, in terms of channel utilization) competitions. The NE existence condition and market entry barriers are also derived. Via an extensive numerical analysis, we show the tradeoffs between leasing/eviction cost, customer arrivals, and channel usage patterns by the legacy users.
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INFOCOM - Wi-Fi 2.0: Price and quality competitions of duopoly cognitive radio wireless service providers with time-varying spectrum availability
2011 Proceedings IEEE INFOCOM, 2011Co-Authors: Jaehyuk Choi, Kang G. ShinAbstract:The whitespaces (WS) in the legacy spectrum provide new opportunities for the future Wi-Fi-like Internet access, often called Wi-Fi 2.0, since service quality can be greatly enhanced thanks to the better propagation characteristics of the WS than the ISM bands. In the Wi-Fi 2.0 networks, each wireless service provider (WSP) temporarily leases a licensed spectrum band from the licensees and opportunistically utilizes it during the absence of the legacy users. The WSPs in Wi-Fi 2.0 thus face unique challenges since spectrum availability of the leased channel is time-varying due to the ON/OFF spectrum usage patterns of the legacy users, which necessitates the eviction control of in-service customers at the return of legacy users. As a result, to maximize its profit, a WSP should consider both channel leasing and eviction costs to optimally determine a spectrum band to lease and a service tariff. In this paper, we consider a duopoly Wi-Fi 2.0 market where two co-located WSPs compete for the spectrum and customers. The competition between the WSPs is analyzed using game theory to derive the Nash Equilibria (NE) of the price (of the service tariffs) and the quality (of the leased channel, in terms of channel utilization) competitions. The NE existence condition and market entry barriers are also derived. Via an extensive numerical analysis, we show the tradeoffs between leasing/eviction cost, customer arrivals, and channel usage patterns by the legacy users.
Qian Zhang - One of the best experts on this subject based on the ideXlab platform.
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Wi-Fi or femtocell: User choice and pricing strategy of wireless service provider
2013 IEEE Global Communications Conference (GLOBECOM), 2013Co-Authors: Yanjiao Chen, Qian ZhangAbstract:Wi-Fi and femtocell are two competing and complementary technologies for delivering broadband wireless Internet access services. For the wireless service provider (WSP) who owns both Wi-Fi and femtocell network, pricing for the coexisted heterogeneous network is a critical yet challenging problem due to different features of the two technologies: Wi-Fi is based on wireless local area network (WLAN), whose time delay is highly dependent on concurrent in-service users; femtocell is based on cellular technology, which provides guaranteed Quality of service (QoS). In this paper, we consider a monopolist WSP who operates both Wi-Fi and femtocell network within a certain area, and offers corresponding services to a fixed pool of users. Users can freely choose either service that incurs less cost, which is a weighted sum of service price and time delay. Users with different sensitivity for price and time delay tend to choose different services. The major objective of WSP is to maximize its profit, which is the revenue from both services. We first analyze user distribution under different Wi-Fi and femtocell price combination, then study the optimal pricing strategy for WSP. Finally, we use simulation to evaluate the influence of Wi-Fi network quality on the WSP's utility and user distribution.
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Utility-Aware Refunding Framework for Hybrid Access Femtocell Network
IEEE Transactions on Wireless Communications, 2012Co-Authors: Yanjiao Chen, Jin Zhang, Qian ZhangAbstract:Femtocell technology addresses the problem of poor indoor coverage, benefiting both wireless service provider (WSP) and end users. With the introduction of femtocell, the cross-tier interference between macro link and femto link becomes a major factor which greatly impacts the network performance. Different access control approaches, by generating different interference patterns, also severely affect the overall throughput of the network and need to be carefully investigated. Among all the access control mechanisms, hybrid access is the most promising one, which allows roaming unregistered users (referred to as macro users) to access the nearby femto base station (BS) while reserving certain resource for registered home users (referred to as femto users), improving overall network capacity. However, to successfully leverage hybrid access is challenging because the femto holders (FHs) are selfish, unwilling to share their femto facilities and spectrum resource with macro users without any incentive mechanism. In this paper, we propose a novel utility-aware refunding framework to motivate hybrid access in femtocell. Within the framework, both WSP and FHs are assumed to be selfish, and target at maximizing their own utilities. WSP provides certain refunding to motivate FHs to open their resource for macro users. FHs decide the resource allocation among femto and macro users according to the amount of refunding WSP offers. Under this framework, the optimal strategies of both WSP and FHs are analyzed by formulating the problem as a Stackelberg Game. A unique Nash Equilibrium is achieved and a hybrid access protocol is designed according to the analysis. Extensive simulations have been conducted and the results show that the utilities of both WSP and FHs are significantly improved exploiting the hybrid access mechanism.
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Optimal Pricing and Spectrum Allocation for wireless service provider on Femtocell Deployment
2011 IEEE International Conference on Communications (ICC), 2011Co-Authors: Yanjiao Chen, Jin Zhang, Qian ZhangAbstract:Femtocell technology is regarded as a promising way to deal with poor indoor coverage and increase spectrum spatial reuse. In this paper, we focus on the scenario that macro and femto base stations are deployed by the same wireless service provider (WSP), which treats the revenue maximization as its ultimate target. In such a system, there are several design factors which will affect the overall revenue, including price decision and resource allocation between macrocell and femtocell. In this paper, we propose an economic framework, where users choose either macrocell or femtocell service to optimize their own utility and the monopolistic WSP tries to maximize its revenue via pricing and spectrum allocation strategy. Theoretical results of optimal prices for macrocell and femtocell are given. Extensive theoretical analysis is carried out to determine the spectrum allocation strategy and evaluate the revenue of the WSP. The system capacity and the ratio of macrocell and femtocell users are also discussed. The results have indicated that the revenue of the WSP is significantly improved by combining the pricing strategy and the spectrum allocation strategy.
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ICC - Optimal Pricing and Spectrum Allocation for wireless service provider on Femtocell Deployment
2011 IEEE International Conference on Communications (ICC), 2011Co-Authors: Yanjiao Chen, Jin Zhang, Qian ZhangAbstract:Femtocell technology is regarded as a promising way to deal with poor indoor coverage and increase spectrum spatial reuse. In this paper, we focus on the scenario that macro and femto base stations are deployed by the same wireless service provider (WSP), which treats the revenue maximization as its ultimate target. In such a system, there are several design factors which will affect the overall revenue, including price decision and resource allocation between macrocell and femtocell. In this paper, we propose an economic framework, where users choose either macrocell or femtocell service to optimize their own utility and the monopolistic WSP tries to maximize its revenue via pricing and spectrum allocation strategy. Theoretical results of optimal prices for macrocell and femtocell are given. Extensive theoretical analysis is carried out to determine the spectrum allocation strategy and evaluate the revenue of the WSP. The system capacity and the ratio of macrocell and femtocell users are also discussed. The results have indicated that the revenue of the WSP is significantly improved by combining the pricing strategy and the spectrum allocation strategy.
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ICC - Bandwidth and Price Competitions of wireless service providers in Two-Stage Spectrum Market
2008 IEEE International Conference on Communications, 2008Co-Authors: Qian ZhangAbstract:Significant technology progress has been witnessed in the research area of dynamic spectrum access. However, the success of dynamic spectrum access will not be possible without the evolution of an spectrum and service market which is both stable and efficient. In this paper, we investigate the dynamic access spectrum from the economic point of view. We study three-layer spectrum market with spectrum holder, wireless service provider and end users. In a duopoly situation, two wireless service providers participate in bandwidth competition to purchase spectrum and price competition to attract end users, with the aim of maximizing their own profit. We formulate the wireless service providers' competition as a two-stage game. Under general assumptions about the pricing and demand functions, a unique equilibrium is identified as the outcome of the game, which shows the stability of the market. We further evaluate the market efficiency in a special case of symmetric wireless service providers and affine pricing and demand functions. The result shows the efficiency of the equilibrium is of reasonable level even with non-cooperative wireless service providers.
Kang Shin - One of the best experts on this subject based on the ideXlab platform.
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Understanding Wi-Fi 2.0: From the economical perspective of wireless service providers
IEEE Wireless Communications, 2010Co-Authors: Hyoil Kim, Kang ShinAbstract:Wi-Fi 2.0 refers to Wi-Fi-like Internet access operating on whitespaces in the licensed spectrum using cognitive radio technology. Wi-Fi 2.0 is expected to provide better performance and larger coverage than today's Wi-Fi, thanks to the good propagation characteristics of the legacy spectrum such as TV bands. Wi-Fi 2.0 is modeled as a network consisting of an access point (called CR hotspot) and end-user terminals (CR devices) operated by a CR wireless service provider. In this article we focus on the economical perspective of Wi-Fi 2.0 and discuss various aspects in profit management of Wi-Fi 2.0 WSPs. In particular, we consider profit-maximizing optimal strategies in terms of customer admission/eviction control and inter-WSP market competition. We first show that Wi-Fi 2.0 operates on time-varying spectrum availability due to the ON-OFF channel usage of legacy users, and advocate the necessity of customer eviction control upon appearance of legacy users. We also identify two types of WSP-WSP market competition in leasing the limited spectrum resources from the licensees and in enticing end customers with a competitive price. Then we enumerate the key factors affecting the profit of collocated WSPs, such as channel leasing cost, service tariff, QoS provisioning, and coexistence with legacy services. By examining Wi-Fi 2.0 from an economic point of view, we show its commercial value in developing next-generation CR applications that benefit both legacy and CR users.
Yanjiao Chen - One of the best experts on this subject based on the ideXlab platform.
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Wi-Fi or femtocell: User choice and pricing strategy of wireless service provider
2013 IEEE Global Communications Conference (GLOBECOM), 2013Co-Authors: Yanjiao Chen, Qian ZhangAbstract:Wi-Fi and femtocell are two competing and complementary technologies for delivering broadband wireless Internet access services. For the wireless service provider (WSP) who owns both Wi-Fi and femtocell network, pricing for the coexisted heterogeneous network is a critical yet challenging problem due to different features of the two technologies: Wi-Fi is based on wireless local area network (WLAN), whose time delay is highly dependent on concurrent in-service users; femtocell is based on cellular technology, which provides guaranteed Quality of service (QoS). In this paper, we consider a monopolist WSP who operates both Wi-Fi and femtocell network within a certain area, and offers corresponding services to a fixed pool of users. Users can freely choose either service that incurs less cost, which is a weighted sum of service price and time delay. Users with different sensitivity for price and time delay tend to choose different services. The major objective of WSP is to maximize its profit, which is the revenue from both services. We first analyze user distribution under different Wi-Fi and femtocell price combination, then study the optimal pricing strategy for WSP. Finally, we use simulation to evaluate the influence of Wi-Fi network quality on the WSP's utility and user distribution.
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Utility-Aware Refunding Framework for Hybrid Access Femtocell Network
IEEE Transactions on Wireless Communications, 2012Co-Authors: Yanjiao Chen, Jin Zhang, Qian ZhangAbstract:Femtocell technology addresses the problem of poor indoor coverage, benefiting both wireless service provider (WSP) and end users. With the introduction of femtocell, the cross-tier interference between macro link and femto link becomes a major factor which greatly impacts the network performance. Different access control approaches, by generating different interference patterns, also severely affect the overall throughput of the network and need to be carefully investigated. Among all the access control mechanisms, hybrid access is the most promising one, which allows roaming unregistered users (referred to as macro users) to access the nearby femto base station (BS) while reserving certain resource for registered home users (referred to as femto users), improving overall network capacity. However, to successfully leverage hybrid access is challenging because the femto holders (FHs) are selfish, unwilling to share their femto facilities and spectrum resource with macro users without any incentive mechanism. In this paper, we propose a novel utility-aware refunding framework to motivate hybrid access in femtocell. Within the framework, both WSP and FHs are assumed to be selfish, and target at maximizing their own utilities. WSP provides certain refunding to motivate FHs to open their resource for macro users. FHs decide the resource allocation among femto and macro users according to the amount of refunding WSP offers. Under this framework, the optimal strategies of both WSP and FHs are analyzed by formulating the problem as a Stackelberg Game. A unique Nash Equilibrium is achieved and a hybrid access protocol is designed according to the analysis. Extensive simulations have been conducted and the results show that the utilities of both WSP and FHs are significantly improved exploiting the hybrid access mechanism.
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Optimal Pricing and Spectrum Allocation for wireless service provider on Femtocell Deployment
2011 IEEE International Conference on Communications (ICC), 2011Co-Authors: Yanjiao Chen, Jin Zhang, Qian ZhangAbstract:Femtocell technology is regarded as a promising way to deal with poor indoor coverage and increase spectrum spatial reuse. In this paper, we focus on the scenario that macro and femto base stations are deployed by the same wireless service provider (WSP), which treats the revenue maximization as its ultimate target. In such a system, there are several design factors which will affect the overall revenue, including price decision and resource allocation between macrocell and femtocell. In this paper, we propose an economic framework, where users choose either macrocell or femtocell service to optimize their own utility and the monopolistic WSP tries to maximize its revenue via pricing and spectrum allocation strategy. Theoretical results of optimal prices for macrocell and femtocell are given. Extensive theoretical analysis is carried out to determine the spectrum allocation strategy and evaluate the revenue of the WSP. The system capacity and the ratio of macrocell and femtocell users are also discussed. The results have indicated that the revenue of the WSP is significantly improved by combining the pricing strategy and the spectrum allocation strategy.
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ICC - Optimal Pricing and Spectrum Allocation for wireless service provider on Femtocell Deployment
2011 IEEE International Conference on Communications (ICC), 2011Co-Authors: Yanjiao Chen, Jin Zhang, Qian ZhangAbstract:Femtocell technology is regarded as a promising way to deal with poor indoor coverage and increase spectrum spatial reuse. In this paper, we focus on the scenario that macro and femto base stations are deployed by the same wireless service provider (WSP), which treats the revenue maximization as its ultimate target. In such a system, there are several design factors which will affect the overall revenue, including price decision and resource allocation between macrocell and femtocell. In this paper, we propose an economic framework, where users choose either macrocell or femtocell service to optimize their own utility and the monopolistic WSP tries to maximize its revenue via pricing and spectrum allocation strategy. Theoretical results of optimal prices for macrocell and femtocell are given. Extensive theoretical analysis is carried out to determine the spectrum allocation strategy and evaluate the revenue of the WSP. The system capacity and the ratio of macrocell and femtocell users are also discussed. The results have indicated that the revenue of the WSP is significantly improved by combining the pricing strategy and the spectrum allocation strategy.
