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120
Auctionbased spectrum sharing
 WiOpt '04
, 2004
"... Abstract. We study auctionbased mechanisms for sharing spectrum among a group of users, subject to a constraint on the interference temperature at collocated receivers. The users access the channel using spread spectrum signaling and thus generate interference with each other. Each user receives a ..."
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Cited by 119 (18 self)
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Abstract. We study auctionbased mechanisms for sharing spectrum among a group of users, subject to a constraint on the interference temperature at collocated receivers. The users access the channel using spread spectrum signaling and thus generate interference with each other. Each user receives a utility that is a function of the received signaltointerference plus noise ratio. We propose two auction mechanisms for allocating the received power. The first is an SINRbased auction, which, when combined with logarithmic utilities, leads to a weighted maxmin fair SINR allocation. The second is a powerbased auction that maximizes the total utility when the bandwidth is large enough. Both auction mechanisms achieve social optimality in a large system limit where bandwidth, power and the number of users are increased in a fixed proportion. We also give sufficient conditions for global convergence of a distributed updating algorithm and discuss the convergence speed. 1
Radio Link Admission Algorithms for Wireless Networks with Power Control and Active Link Quality Protection
 IN PROC. IEEE INFOCOM
, 1994
"... In this paper we present a distributed power control scheme, which maintains the SIRs of operational (active) links above their required thresholds at all time (link quality protection), while new users are being admitted; furthermore, when new users cannot be successfully admitted, existing ones do ..."
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Cited by 96 (5 self)
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In this paper we present a distributed power control scheme, which maintains the SIRs of operational (active) links above their required thresholds at all time (link quality protection), while new users are being admitted; furthermore, when new users cannot be successfully admitted, existing ones do not suffer fluctuations of their SIRs below their required thresholds values. We also present two admission /rejection control algorithms, which exercise voluntary dropout of links inadmissible to the network, so as to reduce interference and possibly facilitate the admission of other links.
Power Control in TwoTier Femtocell Networks
, 2008
"... Two tier cellular networks, comprising of a central macrocell underlaid with short range femtocell hotspots offer an economical way to improve cellular capacity. With shared spectrum and lack of coordination between tiers, crosstier interference limits overall capacity. To quantify nearfar effects ..."
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Cited by 74 (6 self)
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Two tier cellular networks, comprising of a central macrocell underlaid with short range femtocell hotspots offer an economical way to improve cellular capacity. With shared spectrum and lack of coordination between tiers, crosstier interference limits overall capacity. To quantify nearfar effects with universal frequency reuse, this paper derives a fundamental relation providing the largest feasible macrocell SignaltoInterferencePlusNoise Ratio (SINR), given any set of feasible femtocell SINRs. A distributed utilitybased SINR adaptation at femtocells is proposed in order to alleviate crosstier interference at the macrocell from overlaid femtocell infrastructure. The FoschiniMiljanic (FM) algorithm is a special case of the adaptation. Each femtocell maximizes its individual utility consisting of a SINR based reward less an incurred cost (interference to the macrocell). Numerical results show greater than 30 % improvement in mean femtocell SINRs relative to FM. In the event that crosstier interference prevents a macrouser from obtaining its SINR target, an algorithm is proposed that adaptively curtails transmission powers of the strongest femtocell interferers. The algorithm ensures that a macrouser achieves its SINR target even with 100 femtocells/cellsite, and requires a worst case SINR reduction of only 16 % at femtocells. These results motivate design of power control schemes requiring minimal network overhead in twotier networks with shared spectrum.
Soft And Safe Admission Control In Cellular Networks
 IEEE/ACM Transactions on Networking
, 1997
"... We study the mobile admission control problem in a cellular PCS network where transmitter powers are constrained and controlled by a Distributed Constrained Power Control (DCPC) algorithm. Receivers are subject to nonnegligible noise, and the DCPC attempts to bring each receiver's CIR (Carrier ..."
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Cited by 42 (0 self)
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We study the mobile admission control problem in a cellular PCS network where transmitter powers are constrained and controlled by a Distributed Constrained Power Control (DCPC) algorithm. Receivers are subject to nonnegligible noise, and the DCPC attempts to bring each receiver's CIR (Carrier to Interference Ratio) above a given quality target. Two classes of distributed admission controls are considered. One is a NonInteractive Admission Control (NIAC), where an admission decision is instantaneously made based on the system state. The other is an Interactive Admission Control (IAC), under which the new mobile is permitted to interact with one or more potential channels before a decision is made. The algorithms are evaluated with respect to their execution time, and their decision errors. Two types of errors are examined. Type I error, where a new mobile is erroneously accepted and results an outage; and type II error, where a new mobile is erroneously rejected and results in block...
Gradual Removals in Cellular PCS with Constrained Power Control and Noise
, 1996
"... this paper we study the mobile removal problem in a cellular PCS network where transmitter powers are constrained and controlled by a Distributed Constrained Power Control (DCPC) algorithm. Receivers are subject to nonnegligible noise, and the DCPC attempts to bring each receiver's CIR above a ..."
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Cited by 42 (4 self)
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this paper we study the mobile removal problem in a cellular PCS network where transmitter powers are constrained and controlled by a Distributed Constrained Power Control (DCPC) algorithm. Receivers are subject to nonnegligible noise, and the DCPC attempts to bring each receiver's CIR above a given target. To evaluate feasibility and computational complexity, we assume a paradigm where radio bandwidth is scarce and interbase station connection is fast. We show that finding the optimal removal set is an NPComplete problem, giving rise for heuristic algorithms. We study and compare among three classes of transmitter removal algorithms. Two classes consist of algorithms which are invoked only when reaching a stable power vector under DCPC. The third class consist of algorithms which combine transmitter removals with power control. These are Onebyone Removals, Multiple Removals, and Power Control with Removals Combined. In the class of power control with removals combined, we also consider a distributed algorithm which uses the same local information as DCPC does. All removal algorithms are compared with respect to their outage probabilities and their time to converge to a stable state. Comparisons are made in a hexagonal macrocellular system, and in two metropolitan microcellular systems. The
Mathematical decomposition techniques for distributed crosslayer optimization of data networks
 IEEE J. SEL. AREAS COMMUN
, 2006
"... Network performance can be increased if the traditionally separated network layers are jointly optimized. Recently, network utility maximization has emerged as a powerful framework for studying such crosslayer issues. In this paper, we review and explain three distinct techniques that can be used ..."
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Cited by 31 (3 self)
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Network performance can be increased if the traditionally separated network layers are jointly optimized. Recently, network utility maximization has emerged as a powerful framework for studying such crosslayer issues. In this paper, we review and explain three distinct techniques that can be used to engineer utilitymaximizing protocols: primal, dual, and cross decomposition. The techniques suggest layered, but loosely coupled, network architectures and protocols where different resource allocation updates should be run at different timescales. The decomposition methods are applied to the design of fully distributed protocols for two wireless network technologies: networks with orthogonal channels and networkwide resource constraints, as well as wireless networks where the physical layer uses spatialreuse timedivision multiple access. Numerical examples are included to demonstrate the power of the approach.
Distributed power control for time varying wireless networks: Optimality and convergence
 in Proceedings: Allerton Conference on Communications, Control, and Computing
, 2003
"... This paper presents a new distributed power control algorithm for adhoc wireless networks in random channel environments. Previous work in this area has focused on distributed power control for adhoc networks with fixed channels. We show that the algorithms resulting from such formulations do not ..."
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Cited by 23 (1 self)
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This paper presents a new distributed power control algorithm for adhoc wireless networks in random channel environments. Previous work in this area has focused on distributed power control for adhoc networks with fixed channels. We show that the algorithms resulting from such formulations do not accurately capture the dynamics of a timevarying channel. The performance of the network, in terms of power consumption and generated interference, can be severely degraded when a power control algorithm designed for a deterministic channel is applied to a random channel. In particular, some wellknown strong optimality results for such algorithms no longer hold. In order to address these problems we propose a new criterion for power optimality in adhoc wireless networks. We then show that the optimal power allocation for this new criterion can be found through an appropriate stochastic approximation algorithm. Ultimately, the iterations of the stochastic approximation algorithm can be decoupled to form an optimal fully distributed online power control algorithm for adhoc wireless networks with timevarying channels. 1
Mapel: achieving global optimality for a nonconvex power control problem
 IEEE Trans. Wireless Commun
, 2009
"... Abstract—Achieving weighted throughput maximization (WTM) through power control has been a long standing open problem in interferencelimited wireless networks. The complicated coupling between the mutual interferences of links gives rise to a nonconvex optimization problem. Previous work has consi ..."
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Cited by 21 (0 self)
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Abstract—Achieving weighted throughput maximization (WTM) through power control has been a long standing open problem in interferencelimited wireless networks. The complicated coupling between the mutual interferences of links gives rise to a nonconvex optimization problem. Previous work has considered the WTM problem in the high signal to interferenceandnoise ratio (SINR) regime, where the problem can be approximated and transformed into a convex optimization problem through proper change of variables. In the general SINR regime, however, the approximation and transformation approach does not work. This paper proposes an algorithm, MAPEL, which globally converges to a global optimal solution of the WTM problem in the general SINR regime. The MAPEL algorithm is designed based on three key observations of the WTM problem: (1) the objective function is monotonically increasing in SINR, (2) the objective function can be transformed into a product of exponentiated linear fraction functions, and (3) the feasible set of the equivalent transformed problem is always “normal", although not necessarily convex. The MAPEL algorithm finds the desired optimal power control solution by constructing a series of polyblocks that approximate the feasible SINR region in an increasing precision. Furthermore, by tuning the approximation factor in MAPEL, we could engineer a desirable tradeoff between optimality and convergence time. MAPEL provides an important benchmark for performance evaluation of other heuristic algorithms targeting the same problem. With the help of MAPEL, we evaluate the performance of several existing algorithms through extensive simulations.
Distributed power and admission control for timevarying wireless networks
 in Proc. IEEE International Symposium on Information Theory (ISIT
, 2004
"... Abstract — This paper presents new distributed power and admission control algorithms for adhoc wireless networks in random channel environments. Previous work in this area has focused on distributed control for adhoc networks with fixed channels. We show that the algorithms resulting from such fo ..."
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Cited by 19 (0 self)
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Abstract — This paper presents new distributed power and admission control algorithms for adhoc wireless networks in random channel environments. Previous work in this area has focused on distributed control for adhoc networks with fixed channels. We show that the algorithms resulting from such formulations do not accurately capture the dynamics of a timevarying channel. The performance of the network in terms of power consumption and generated interference, can be severely degraded when power and admission control algorithms that are designed for deterministic channels are applied to random channels. In particular, some wellknown optimality results for deterministic channels no longer hold. In order to address these problems we propose a new criterion for power optimality in adhoc wireless networks. We then show that the optimal power allocation for this new criterion can be found through an appropriate stochastic approximation algorithm. We also present a modified version of this algorithm for tracking nonstationary equilibria, which allows us to perform admission control. Ultimately, the iterations of the stochastic approximation algorithms can be decoupled to form fully distributed online power and admission control algorithms for adhoc wireless networks with timevarying channels. I.
A SelfLearning Call Admission Control Scheme for CDMA Cellular Networks
 IEEE TRANSACTIONS ON NEURAL NETWORKS
, 2005
"... In the present paper, a call admission control scheme that can learn from the network environment and user behavior is developed for code division multiple access (CDMA) cellular networks that handle both voice and data services. The idea is built upon a novel learning control architecture with onl ..."
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Cited by 19 (8 self)
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In the present paper, a call admission control scheme that can learn from the network environment and user behavior is developed for code division multiple access (CDMA) cellular networks that handle both voice and data services. The idea is built upon a novel learning control architecture with only a single module instead of two or three modules in adaptive critic designs (ACDs). The use of adaptive critic approach for call admission control in wireless cellular networks is new. The call admission controller can perform learning in realtime as well as in offline environments and the controller improves its performance as it gains more experience. Another important contribution in the present work is the choice of utility function for the present selflearning control approach which makes the present learning process much more efficient than existing learning control methods. The performance of our algorithm will be shown through computer simulation and compared with existing algorithms.