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Endtoend QoS for video delivery over wireless Internet
 Proceedings of the IEEE
, 2005
"... Providing endtoend quality of service (QoS) support is essential for video delivery over the nextgeneration wireless Internet. In this paper, we address several key elements in the endtoend QoS support, including scalable video representation, networkaware end system, and network QoS provision ..."
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Cited by 36 (0 self)
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Providing endtoend quality of service (QoS) support is essential for video delivery over the nextgeneration wireless Internet. In this paper, we address several key elements in the endtoend QoS support, including scalable video representation, networkaware end system, and network QoS provisioning. There are generally two approaches in QoS support: the networkcentric and the endsystem centric solutions. The fundamental problem in a networkcentric solution is how to map QoS criterion at different layers respectively, and optimize total quality across these layers. In this paper, we first present the general framework of a crosslayer networkcentric solution, and then describe the recent advances in network modeling, QoS mapping, and QoS adaptation. The key targets in endsystem centric approach are network adaptation and media adaptation.In this paper, we present a general framework of the endsystem centric solution and investigate the recent developments. Specifically, for network adaptation, we review the available bandwidth estimation and efficient video transport protocol; for media adaptation, we describe the advances in error control, power control, and corresponding bit allocation. Finally, we highlight several advanced research directions.
Stochastic learning solution for distributed discrete power control game in wireless data networks
, 2008
"... Distributed power control is an important issue in wireless networks. Recently, noncooperative game theory has been applied to investigate interesting solutions to this problem. The majority of these studies assumes that the transmitter power level can take values in a continuous domain. However, r ..."
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Cited by 28 (0 self)
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Distributed power control is an important issue in wireless networks. Recently, noncooperative game theory has been applied to investigate interesting solutions to this problem. The majority of these studies assumes that the transmitter power level can take values in a continuous domain. However, recent trends such as the GSM standard and Qualcomm’s proposal to the IS95 standard use a finite number of discretized power levels. This motivates the need to investigate solutions for distributed discrete power control which is the primary objective of this paper. We first note that, by simply discretizing, the previously proposed continuous power adaptation techniques will not suffice. This is because a simple discretization does not guarantee convergence and uniqueness. We propose two probabilistic power adaptation algorithms and analyze their theoretical properties along with the numerical behavior. The distributed discrete power control problem is formulated as anperson, nonzero sum game. In this game, each user evaluates a power strategy by computing a utility value. This evaluation is performed using a stochastic iterative procedures. We approximate the discrete power control iterations by an equivalent ordinary differential equation to prove that the proposed stochastic learning power control algorithm converges to a stable Nash equilibrium. Conditions when more than one stable Nash equilibrium or even only mixed equilibrium may exist are also studied. Experimental results are presented for several cases and compared with the continuous power level adaptation solutions.
Scheduling, routing and power allocation for fairness in wireless networks
 IEEE Vehicular Technology Conference
, 2004
"... Abstract — We consider the problem of finding the jointly optimal endtoend communication rates, routing, power allocation and transmission scheduling for wireless networks. We focus on throughput and fairness between endtoend rates and formulate the associated crosslayer design problem as a non ..."
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Cited by 21 (2 self)
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Abstract — We consider the problem of finding the jointly optimal endtoend communication rates, routing, power allocation and transmission scheduling for wireless networks. We focus on throughput and fairness between endtoend rates and formulate the associated crosslayer design problem as a nonlinear mathematical program. We develop a specialized solution method, based on a nonlinear column generation technique, that applies to a wide range of media access schemes and converges to the optimal solution in a finite number of steps. The approach is applied to a large set of sample networks and the influence of power control, spatial reuse, routing strategies and variable transmission rates on network performance is discussed. I.
Discrete power control: Cooperative and noncooperative optimization
 IN INFOCOM
, 2007
"... We consider an uplink power control problem where each mobile wishes to maximize its throughput (which depends on the transmission powers of all mobiles) but has a constraint on the average power consumption. A finite number of power levels are available to each mobile. The decision of a mobile to ..."
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Cited by 16 (3 self)
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We consider an uplink power control problem where each mobile wishes to maximize its throughput (which depends on the transmission powers of all mobiles) but has a constraint on the average power consumption. A finite number of power levels are available to each mobile. The decision of a mobile to select a particular power level may depend on its channel state. We consider two frameworks concerning the state information of the channels of other mobiles: (i) the case of full state information and (ii) the case of local state information. In each of the two frameworks, we consider both cooperative as well as noncooperative power control. We manage to characterize the structure of equilibria policies and, more generally, of bestresponse policies in the noncooperative case. We present an algorithm to compute equilibria policies in the case of two noncooperative players. Finally, we study the case where a malicious mobile, which also has average power constraints, tries to jam the communication of the other mobile. Our results are illustrated and validated through various numerical examples.
Prioritized Throughput Maximization via Rate and Power Control for 3G CDMA: The 2 Terminal Scenario
 Proc. of 40th Allerton Conf. on Comm., Control and Comp
, 2002
"... Variable spreading gain (VSG) CDMA allows data terminals to operate at dissimilar transmission rates. With this technique, the chip rate is common to all users, but the spreading gains vary. Our work is relevant to the uplink of a singlecell VSG CDMA system, in which each terminal’s data throughput ..."
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Cited by 7 (6 self)
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Variable spreading gain (VSG) CDMA allows data terminals to operate at dissimilar transmission rates. With this technique, the chip rate is common to all users, but the spreading gains vary. Our work is relevant to the uplink of a singlecell VSG CDMA system, in which each terminal’s data throughput is weighted differently in calculating the network throughput. We seek for each active user a power level and transmission rate which will maximize the network’s aggregate weighted throughput. This paper focuses on the twoterminal, interferencelimited scenario. The development is entirely analytical, based on optimization theory. One of the principal results is that the favorite terminal should always operate at the highest data rate. The optimal bit rate of the other terminal depends on the ratio of the minimum allowable spreading gain to the square root of the priority coefficient. Only when this ratio is large enough, is it optimal for both terminals to operate at the highest permissible data rate. In either case, we provide equations whose solutions lead to the optimal power ratios. 1
Dynamic Discrete Power Control in Cellular Networks
"... We consider an uplink power control problem where each mobile wishes to maximize its throughput (which depends on the transmission powers of all mobiles) but has a constraint on the average power consumption. A finite number of power levels are available to each mobile. The decision of a mobile to ..."
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Cited by 7 (3 self)
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We consider an uplink power control problem where each mobile wishes to maximize its throughput (which depends on the transmission powers of all mobiles) but has a constraint on the average power consumption. A finite number of power levels are available to each mobile. The decision of a mobile to select a particular power level may depend on its channel state. We consider two frameworks concerning the state information of the channels of other mobiles: (i) the case of full state information and (ii) the case of local state information. In each of the two frameworks, we consider both cooperative as well as noncooperative power control. We manage to characterize the structure of equilibria policies and, more generally, of bestresponse policies in the noncooperative case. We present an algorithm to compute equilibria policies in the case of two noncooperative players. Finally, we study the case where a malicious mobile, which also has average power constraints, tries to jam the communication of another mobile. Our results are illustrated and validated through various numerical examples.
Power Control and Transmission Rate Management in Cellular Radio Systems
, 1999
"... The scarce radio spectrum imposes hard limitations on design of cellular radio systems. To provide communication services with high capacity and good quality of service requires powerful methods for sharing the radio spectrum in most efficient way. In practice, all sharing methods introduce int ..."
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Cited by 6 (0 self)
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The scarce radio spectrum imposes hard limitations on design of cellular radio systems. To provide communication services with high capacity and good quality of service requires powerful methods for sharing the radio spectrum in most efficient way. In practice, all sharing methods introduce interference, which is proportional to the transmitter powers. The transmitter power control is a key technique to balance the received signal strength and the interference power, which in turn enables more efficient sharing. Emerging
Joint link quality and power management over wiereless networks with fairness constraint and spacetime dversity
 IEEE Trans. Veh. Technology
, 2004
"... Abstract—In multiaccess wireless networks, dynamic allocation of resource such as link qualities and transmitted powers is an important means to combat timevarying fading environments and cochannel interferences (CCIs). In most prior work, every link’s quality is maintained by having a fixed signal ..."
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Cited by 5 (0 self)
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Abstract—In multiaccess wireless networks, dynamic allocation of resource such as link qualities and transmitted powers is an important means to combat timevarying fading environments and cochannel interferences (CCIs). In most prior work, every link’s quality is maintained by having a fixed signaltointerferencenoiseratio (SINR) requirement. We discover that such a constraint is too strong and can degrade the performance of entire wireless networks, because a user with a bad channel response requires too much transmitted power and, therefore, causes unnecessary CCI to other users. In this paper, we alleviate this constraint and explore the time and multiuser diversity. For each user, the timeaverage link quality is maintained as a constant to ensure fairness. For the whole system, we want to minimize the overall transmitted power. In order to solve this problem, each user provides the system with a SINR range that is acceptable, according to the channel conditions and transmission history. Then, the system allocates the resources according to these ranges, channel conditions, and other practical constraints. Each time, some users may sacrifice their performances to reduce the overall network transmitted power. These users ’ temporary sacrifices will improve the system performance and will be paid back in the long term. This scheme can be conceived of as “water filling ” the wireless network resources to different users at different times. In addition, by combining the proposed scheme with beamforming, we can have one more degree of freedom to combat CCIs in different directions of arrivals and different channel conditions over time. Index Terms—antenna arrays, communication networks, diversity methods, power control, resource management. I.
Performance enhancement of joint adaptive modulation, coding and power control using cochannelinterferer assistance and channel reallocation
 in IEEE Wireless Communications and Networking Conference (WCNC
, 2003
"... AbstractThis paper proposes a joint adaptive rate selection and power control algorithm for broadband TDMA/TDM wireless networks. The proposed algorithm is a modified, enhanced, and more robust version of the Selective Power Control with Active Link Protection (SPCALP) algorithm proposed for adapt ..."
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Cited by 5 (1 self)
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AbstractThis paper proposes a joint adaptive rate selection and power control algorithm for broadband TDMA/TDM wireless networks. The proposed algorithm is a modified, enhanced, and more robust version of the Selective Power Control with Active Link Protection (SPCALP) algorithm proposed for adaptive transmission rate and power control in CDMA networks [1]. Unlike SPCALP, the proposed algorithm uses adaptive coding and modulation (instead of variable spreading gain) for transmission rate control. In addition, the proposed algorithm is different in two aspects; the first one is the inclusion of the cochannel interferer assistance mode, while the second one is the use of the signal quality as a criterion for user removal. Results show that the proposed algorithm outperforms SPCALP in terms of the net throughput and signal quality measures such as the outage probability and frame error rate. Channel reallocation is also studied and found to be very effective in enhancing the system performance particularly at low to medium loading. I.
Fairness Enhancement of Link Adaptation Techniques in Wireless Access Networks
"... Abstract—Link adaptation techniques, such as power control and adaptive coding and modulation, aim at maximizing the throughput in wireless networks while maintaining the signal quality in terms of the signal to interference ratio. However, fair resource allocation among different users must be take ..."
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Abstract—Link adaptation techniques, such as power control and adaptive coding and modulation, aim at maximizing the throughput in wireless networks while maintaining the signal quality in terms of the signal to interference ratio. However, fair resource allocation among different users must be taken into consideration, particularly in fixed broadband wireless access networks. The low/no mobility of users in such networks can lead to locationdependent resource utilization, which causes a significant variation in the performance from a user to another. For instance, adaptive coding and modulation schemes increase the aggregate throughput in the network; however, they also increase the variation of the throughput among users. In this paper, we propose, and analyze the performance of, three fairness enhancement schemes that can be integrated with link adaptation techniques. Results show that the three proposed scheme can enhance the fairness of link adaptation techniques with different degrees without causing (or with minor) degradation to the total network throughput. Keywordsfairness; link adaptation techniques; adaptive power control; adaptive coding and modulation; radio resource management I.