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Efficient power control via pricing in wireless data networks
 IEEE Trans. on Commun
, 2002
"... Abstract—A major challenge in the operation of wireless communications systems is the efficient use of radio resources. One important component of radio resource management is power control, which has been studied extensively in the context of voice communications. With the increasing demand for wir ..."
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Abstract—A major challenge in the operation of wireless communications systems is the efficient use of radio resources. One important component of radio resource management is power control, which has been studied extensively in the context of voice communications. With the increasing demand for wireless data services, it is necessary to establish power control algorithms for information sources other than voice. We present a power control solution for wireless data in the analytical setting of a game theoretic framework. In this context, the quality of service (QoS) a wireless terminal receives is referred to as the utility and distributed power control is a noncooperative power control game where users maximize their utility. The outcome of the game results in a Nash equilibrium that is inefficient. We introduce pricing of transmit powers in order to obtain Pareto improvement of the noncooperative power control game, i.e., to obtain improvements in user utilities relative to the case with no pricing. Specifically, we consider a pricing function that is a linear function of the transmit power. The simplicity of the pricing function allows a distributed implementation where the price can be broadcast by the base station to all the terminals. We see that pricing is especially helpful in a heavily loaded system. Index Terms—Game theory, Pareto efficiency, power control, pricing, wireless data. I.
Downlink Power Allocation for Multiclass CDMA Wireless Networks
, 2002
"... In this paper we consider the downlink power allocation problem for multiclass CDMA wireless networks. We use a utility based power allocation framework to treat multiclass services in a unified way. The goal of this paper is to obtain a power allocation which maximizes the total system utility. I ..."
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Cited by 50 (4 self)
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In this paper we consider the downlink power allocation problem for multiclass CDMA wireless networks. We use a utility based power allocation framework to treat multiclass services in a unified way. The goal of this paper is to obtain a power allocation which maximizes the total system utility. In the wireless context, natural utility functions for each mobile are nonconcave. Hence, we cannot use existing techniques on convex optimization problems to derive a social optimal solution. We propose a simple distributed algorithm to obtain an approximation to the social optimal power allocation. The proposed distributed algorithm is based on dynamic pricing and allows partial cooperation between mobiles and the base station. The algorithm consists of two stages. At the mobile selection stage, the base station selects mobiles to which power is allocated, considering the partialcooperative nature of mobiles. This is called partialcooperative optimal selection, since in a partialcooperative setting and pricing scheme considered in this paper, this selection is optimal and satisfies system feasibility. At the power allocation stage, the base station allocates power to the selected mobiles. This power allocation is a social optimal power allocation among mobiles in the partialcooperative optimal selection, thus, we call it a partialcooperative optimal power allocation. We compare the partialcooperative optimal power allocation with the social optimal power allocation for the single class case. From these results, we infer that the system utility obtained by the partialcooperative optimal power allocation is quite close to the system utility obtained by the social optimal allocation.
Joint Resource Allocation and BaseStation Assignment for the Downlink in CDMA Networks
"... In this paper, we consider the joint resource allocation and basestation assignment problem for the downlink in CDMA networks with heterogeneous data services. We first study a power and rate control problem that attempts to maximize the expected throughput of the system. This problem is inherent ..."
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Cited by 10 (0 self)
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In this paper, we consider the joint resource allocation and basestation assignment problem for the downlink in CDMA networks with heterogeneous data services. We first study a power and rate control problem that attempts to maximize the expected throughput of the system. This problem is inherently difficult because it is in fact a nonconvex optimization problem. To solve this problem, we propose a distributed algorithm based on dynamic pricing.
Orthogonal polynomials associated with root systems,Preprint(1988
 the IEEE Journal on Selected Areas in Communications
, 2006
"... Recent research in wireless CDMA systems has shown that adaptive rate/power control can considerably increase network throughput relative to systems that use only power or rate control. In this paper, we consider joint power/rate optimization in the context of orthogonal modulation (OM) and investig ..."
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Cited by 2 (0 self)
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Recent research in wireless CDMA systems has shown that adaptive rate/power control can considerably increase network throughput relative to systems that use only power or rate control. In this paper, we consider joint power/rate optimization in the context of orthogonal modulation (OM) and investigate the additional performance gains achieved through adaptation of the OM order. We show that such adaptation can significantly increase network throughput while simultaneously reducing the perbit energy consumption relative to fixedorder modulation systems. The optimization is carried out under two different objective functions: minimizing the maximum service time and maximizing the sum of user rates. For the first objective function, we prove that the optimization problem can be formulated as a generalized geometric program (GGP). We then show how this GGP can be transformed into a nonlinear convex program, which can be solved optimally and efficiently. For the second objective function, we obtain a lower bound on the performance gain of adaptive OM (AOM) over fixedmodulation systems. Numerical results indicate that relative to an optimal joint rate/power control fixedorder modulation scheme, the proposed AOM scheme achieves significant throughput and energy gains. I.
Analyzing Wireless Networks
, 2000
"... In recent years, the number and variety of wireless network installations have dramatically increased, from smallscale installations spanning buildings and campuses to much largerscale installations spanning cities and metropolitan areas. As these wireless networks proliferate, the population of u ..."
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Cited by 2 (1 self)
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In recent years, the number and variety of wireless network installations have dramatically increased, from smallscale installations spanning buildings and campuses to much largerscale installations spanning cities and metropolitan areas. As these wireless networks proliferate, the population of users taking advantage of these networks for communication and access to online services and information also increases. To aid this growing population of users, many research and development efforts focus on upgrading and enhancing the services provided to the users. As part of these efforts, it is crucial to analyze real wireless networks to understand better how users take advantage of them. These analyses are important for at least two reasons. First, they are helpful for creating more realistic models of users when simulating new services, which is a common technique used in the mobile networking community to predict performance. Second, they are also helpful in focusing research on topics that will impact users the most. This thesis analyzes two very different wireless networks: the Metricom Ricochet packet radio network, a high latency, low bandwidth, metropolitanarea wireless network, and the WaveLAN network installed in the Gates Computer Science Building, a low latency, high bandwidth, localarea network. These analyses answer questions about network utilization, traffic characteristics, and user mobility rates and patterns. Among other results, we find that traffic peaks are usually caused by a single user rather than multiple users, and that significantly asymmetric network throughput would be undesirable for the WaveLAN network users. We also determine that users can indeed be categorized based on their mobility in the Metricom analysis and based on their usage ...
Downlink Throughput Maximization in CDMA Wireless Networks
, 2004
"... We investigate optimum rate assignment scheme maximizing network throughput on the downlink of a multirate CDMA wireless network. Systems employing orthogonal variable spreading factor (OVSF) codes as well as systems employing multiple codes have been studied. Our objective is to maximize the networ ..."
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Cited by 1 (0 self)
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We investigate optimum rate assignment scheme maximizing network throughput on the downlink of a multirate CDMA wireless network. Systems employing orthogonal variable spreading factor (OVSF) codes as well as systems employing multiple codes have been studied. Our objective is to maximize the network throughput under constraints on total transmit power, total bandwidth and individual QoS requirements specified in terms of minimum rates. First, users are ordered based on their transmit energy per bit requirements to achieve the target received energy per bit to interference power spectral density ratio at the receivers. Based on the initial ordering, we prove that for systems employing multiple codes, greedy rate scheduling yields maximum network throughput. For systems employing variable spreading codes, we show that greedy rate scheduling is optimal if the minimum rate requirement of a user is larger than or equal to the minimum rate requirement of any other user with a larger transmit energy per bit requirement. Simulation results verify the superiority of the greedy algorithm under various system and channel assumptions.
doi:10.1155/2007/76193 Research Article A UtilityBased Downlink Radio Resource Allocation for Multiservice Cellular DSCDMA Networks
, 2007
"... A novel framework is proposed to model downlink resource allocation problem in multiservice directsequence code division multipleaccess (DSCDMA) cellular networks. This framework is based on a defined utility function, which leads to utilizing the network resources in a more efficient way. This u ..."
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A novel framework is proposed to model downlink resource allocation problem in multiservice directsequence code division multipleaccess (DSCDMA) cellular networks. This framework is based on a defined utility function, which leads to utilizing the network resources in a more efficient way. This utility function quantifies the degree of utilization of resources. As a matter of fact, using the defined utility function, users ’ channel fluctuations and their delay constraints along with the load conditions of all BSs are all taken into consideration. Unlike previous works, we solve the problem with the general objective of maximizing the total network utility instead of maximizing the achieved utility of each base station (BS). It is shown that this problem is equivalent to finding the optimum BS assignment throughout the network, which is mapped to a multidimensional multiplechoice knapsack problem (MMKP). Since MMKP is NPhard, a polynomialtime suboptimal algorithm is then proposed to develop an efficient basestation assignment. Simulation results indicate a significant performance improvement in terms of achieved utility and packet drop ratio. Copyright © 2007 Mahdi Shabany et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1.
Modeling UpLink Power Control with Outage Probabilities
, 2007
"... We investigate models for uplink interference in wireless systems. Our models account for the effects of outage probabilities. Such an accounting requires a nonlinear, even nonconvex model, since increasing interference at the receiving base station increases both mobile transmit power and outage pr ..."
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We investigate models for uplink interference in wireless systems. Our models account for the effects of outage probabilities. Such an accounting requires a nonlinear, even nonconvex model, since increasing interference at the receiving base station increases both mobile transmit power and outage probability, and this results in a complex interaction. Our system model always has at least one solution, a fixed point, and it is provably unique under certain reasonable conditions. Our main purpose is to model real wireless systems as accurately as possible, and so we test our models on realistic scenarios using data from a sophisticated simulator. Our algorithm for finding a fixed point works very well on such scenarios, and is guaranteed to find the fixed point when we can prove it is unique. A slightly simplified model reduces the main data structure for a Ksector market to 16K 2 bytes of memory. 1
Downlink Power Allocation for Multiclass CDMA
"... In this paper we consider the downlink power allocation problem for multiclass CDMA wireless networks. We use a utility based power allocation framework to treat multiclass services in a unified way. The goal of this paper is to obtain a power allocation which maximizes the total system utility. I ..."
Abstract
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In this paper we consider the downlink power allocation problem for multiclass CDMA wireless networks. We use a utility based power allocation framework to treat multiclass services in a unified way. The goal of this paper is to obtain a power allocation which maximizes the total system utility. In the wireless context, natural utility functions for each mobile are nonconcave. Hence, we cannot use existing techniques on convex optimization problems to derive a social optimal solution. We propose a simple distributed algorithm to obtain an approximation to the social optimal power allocation. The proposed distributed algorithm is based on dynamic pricing and allows partial cooperation between mobiles and the base station. The algorithm consists of two stages. At the mobile selection stage, the base station selects mobiles to which power is allocated, considering the partialcooperative nature of mobiles. This is called partialcooperative optimal selection, since in a partialcooperative setting and pricing scheme considered in this paper, this selection is optimal and satisfies system feasibility. At the power allocation stage, the base station allocates power to the selected mobiles. This power allocation is a social optimal power allocation among mobiles in the partialcooperative optimal selection, thus, we call it a partialcooperative optimal power allocation. We compare the partialcooperative optimal power allocation with the social optimal power allocation for the single class case. From these results, we infer that the system utility obtained by the partialcooperative optimal power allocation is quite close to the system utility obtained by the social optimal allocation.