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Reinforcement Learning for Dynamic Channel Allocation in Cellular Telephone Systems
"... In cellular telephone systems, an important problem is to dynamically allocate the communication resource (channels) so as to maximize service in a stochastic caller environment. This problem is naturally formulated as a dynamic programming problem and we use a reinforcement learning (RL) method to ..."
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Cited by 141 (6 self)
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In cellular telephone systems, an important problem is to dynamically allocate the communication resource (channels) so as to maximize service in a stochastic caller environment. This problem is naturally formulated as a dynamic programming problem and we use a reinforcement learning (RL) method to find dynamic channel allocation policies that are better than previous heuristic solutions. The policies obtained perform well for a broad variety of call traffic patterns. We present results on a large cellular system with approximately 49^49 states.
InformationTheoretic Considerations for Symmetric, Cellular, MultipleAccess Fading Channels  Part II
, 1997
"... A simple idealized linear (and planar) uplink, cellular, multipleaccess communication model, where only adjacent cell interference is present and all signals may experience fading is considered. Shannon theoretic arguments are invoked to gain insight into the implications on performance of the main ..."
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Cited by 105 (1 self)
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A simple idealized linear (and planar) uplink, cellular, multipleaccess communication model, where only adjacent cell interference is present and all signals may experience fading is considered. Shannon theoretic arguments are invoked to gain insight into the implications on performance of the main system parameters and multipleaccess techniques. The model treated in Part I [1] is extended here to account for cellsite receivers that may process also the received signal at an adjacent cell site, compromising thus between the advantage of incorporating additional information from other cell sites on one hand and the associated excess processing complexity on the other. Various settings which include fading, timedivision multiple access (TDMA), wideband (WB), and (optimized) fractional intercell time sharing (ICTS) protocols are investigated and compared. In this case and for the WB approach and a large number of users per cell it is found, surprisingly, that fading may enhance performance in terms of Shannon theoretic achievable rates. The linear model is extended to account for general linear and planar configurations. The effect of a random number of users per cell is investigated and it is demonstrated that randomization is beneficial. Certain aspects of diversity as well as some features of TDMA and orthogonal codedivision multiple access (CDMA) techniques in the presence of fading are studied in an isolated cell scenario.
Cellular performance bounds via shotgun cellular systems
 IEEE Journal on Selected Areas in Communications
, 2000
"... This paper considers twodimensional interferencelimited cellular radio systems. It introduces the shotgun cellular system that places base stations randomly and assigns channels randomly. Such systems are shown to provide lower bounds to cellular performance that are easy to compute, independent o ..."
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Cited by 43 (2 self)
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This paper considers twodimensional interferencelimited cellular radio systems. It introduces the shotgun cellular system that places base stations randomly and assigns channels randomly. Such systems are shown to provide lower bounds to cellular performance that are easy to compute, independent of shadow fading, and apply to a number of design scenarios. Traditional hexagonal systems provide an upper performance bound. The difference between upper and lower bounds is small under operating conditions typical in modern TDMA and CDMA cellular systems. Furthermore, in the strong shadow fading limit the bounds converge. To give insights into the design of practical systems, several variations are explored including mobile access methods, sectorizing, channel assignments, and placement with deviations. Together these results indicate cellular performance is very robust and little is lost in making rapid minimallyplanned deployments.
WorstCase Performance of Cellular Channel Assignment Policies
 Wireless Networks
, 1996
"... this paper, we introduce two such metrics: the worstcase number of channels required to accommodate all possible configurations of N calls in a cell cluster, and the set of cell states that can be accommodated with M channels. We first measure two extreme policies, fixed channel allocation and maxi ..."
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Cited by 24 (2 self)
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this paper, we introduce two such metrics: the worstcase number of channels required to accommodate all possible configurations of N calls in a cell cluster, and the set of cell states that can be accommodated with M channels. We first measure two extreme policies, fixed channel allocation and maximum packing, under these metrics. We then prove a new lower bound, under the first metric, on any channel assignment policy. Next, we introduce three intermediate channel assignment policies, based on commonly used ideas of channel ordering, hybrid assignment, and partitioning. Finally, these policies are used to demonstrate the tradeoff between the performance and the complexity of a channel allocation policy. 1 Introduction
Hypergraph models for cellular mobile communication systems
 IEEE Transactions on Vehicular Technology
, 1998
"... endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution m ..."
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Cited by 17 (2 self)
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endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubspermissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.
Channel Assignment Algorithms Satisfying Cochannel and Adjacent Channel Reuse Constraints in Cellular Mobile Networks
, 1998
"... Recently improved channel assignment algorithms for cellular networks were designed by modelling the interference constraints in terms of a hypergraph [1]. However these algorithms only considered cochannel reuse constraints. Receiver filter responses impose restrictions on simultaneous adjacent cha ..."
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Cited by 9 (0 self)
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Recently improved channel assignment algorithms for cellular networks were designed by modelling the interference constraints in terms of a hypergraph [1]. However these algorithms only considered cochannel reuse constraints. Receiver filter responses impose restrictions on simultaneous adjacent channel usage in the same cell or in neighbouring cells. We first present some heuristics for designing fixed channel assignment algorithms with a minimum number of channels satisfying both cochannel and adjacent channel reuse constraints. An asymptotically tight upper bound for the traffic carried by the system in the presence of arbitrary cochannel and adjacent channel reuse constraints was developed in [2]. However this bound is computationally intractable even for small systems like a regular hexagonal cellular system of 19 cells. We have obtained approximations to this bound using the optimal solutions for cochannel reuse constraints only, and a further graph theoretic approach. Our approximations are computationally much more efficient and have turned out to track very closely the exact performance bounds in most cases of interest.
Fairness in Cellular Mobile Networks
"... Channel allocation algorithms for channelized cellular systems are discussed from a new perspective, viz., fairness of allocation. The concepts of relative and absolute fairness are introduced and discussed. It will be shown that under certain reasonable assumptions, there exists an absolute (max ..."
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Cited by 9 (6 self)
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Channel allocation algorithms for channelized cellular systems are discussed from a new perspective, viz., fairness of allocation. The concepts of relative and absolute fairness are introduced and discussed. It will be shown that under certain reasonable assumptions, there exists an absolute (maxmin) fair carried traffic intensity vector (a vector describing the traffic carried in the cells of the system). We also show that this vector is unique. We describe some properties of the maxmin fair carried traffic intensity vector in an asymptotic limit where the traffic and the number of channels are scaled together. For each traffic pattern, we determine affixed channel allocation which attains this maxmin fair carried traffic intensity vector independent of the value of the oered traffic, in the same asymptotic limit. Finally we discuss a tradeoff between being maxmin fair and trying to maximize revenue. We conclude this paper by discussing some possible extensions of our work.
Finding Large Independent Sets of Hypergraphs in Parallel
"... A basic problem in hypergraphs is that of finding a large independent set–one of guaranteed size–in a given hypergraph. Understanding the parallel complexity of this and related independent set problems on hypergraphs is a fundamental open issue in parallel computation. Caro and Tuza (J. Graph Theor ..."
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Cited by 5 (0 self)
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A basic problem in hypergraphs is that of finding a large independent set–one of guaranteed size–in a given hypergraph. Understanding the parallel complexity of this and related independent set problems on hypergraphs is a fundamental open issue in parallel computation. Caro and Tuza (J. Graph Theory, Vol. 15, pp. 99–107, 1991) have shown a certain lower bound αk(H) on the size of a maximum independent set in a given kuniform hypergraph H, and have also presented an efficient sequential algorithm to find an independent set of size αk(H). They also show that αk(H) is the size of the maximum independent set for various hypergraph families. Here, we develop the first RNC algorithm to find an independent set of size αk(H), and also derandomize it for various special cases. We also present lower bounds on independent set size and corresponding RNC algorithms for nonuniform hypergraphs.
Asymptotic Performance Limits for Routing and Rate Allocation In RateBased MultiClass Networks
 In Proc. IEEE GLOBECOM
, 2002
"... In this paper we investigate the performance of Routing and Rate Allocation (RRA) algorithms in ratebased multiclass networks, in particular, a network of routers that support the IntServ Guaranteed Services. We measure the performance of an RRA algorithm in terms of its weighted carried traffic. W ..."
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Cited by 3 (2 self)
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In this paper we investigate the performance of Routing and Rate Allocation (RRA) algorithms in ratebased multiclass networks, in particular, a network of routers that support the IntServ Guaranteed Services. We measure the performance of an RRA algorithm in terms of its weighted carried traffic. We derive an upper bound on the weighted carried traffic of any RRA algorithm. The bound can be computed by linear programming. Moreover we show that a Fixed RRA algorithm achieves the bound asymptotically. Therefore the bound can be used as an absolute benchmark for the performance of various RRA algorithms. We illustrate this by comparing the simulated performance of a simple shortestpath RRA (SPRRA) algorithm with the bound.