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244
Optimal Energy Allocation for DelayConstrained Data Transmission over a TimeVarying Channel
, 2003
"... We seek to maximize the data throughput of an energy and time constrained transmitter sending data over a fading channel. The transmitter has a fixed amount of energy and a limited amount of time to send data. Given that the channel fade state determines the throughput obtained per unit of energy ex ..."
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Cited by 39 (5 self)
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We seek to maximize the data throughput of an energy and time constrained transmitter sending data over a fading channel. The transmitter has a fixed amount of energy and a limited amount of time to send data. Given that the channel fade state determines the throughput obtained per unit of energy expended, the goal is to obtain a policy for scheduling transmissions that maximizes the expected data throughput. We develop a dynamic programming formulation that leads to an optimal closedform transmission schedule. We then extend our approach to the problem of minimizing the energy required to send a fixed amount of data over a fading channel given deadline constraints.
SuperFast Delay Tradeoffs for Utility Optimal Fair Scheduling in Wireless Networks
, 2006
"... We consider the fundamental delay tradeoffs for utility optimal scheduling in a general network with time varying channels. A network controller acts on randomly arriving data and makes flow control, routing, and resource allocation decisions to maximize a fairness metric based on a concave utilit ..."
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Cited by 35 (17 self)
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We consider the fundamental delay tradeoffs for utility optimal scheduling in a general network with time varying channels. A network controller acts on randomly arriving data and makes flow control, routing, and resource allocation decisions to maximize a fairness metric based on a concave utility function of network throughput. A simple set of algorithms are constructed that yield total utility within O(1/V) of the utilityoptimal operating point, for any control parameter V> 0, with a corresponding endtoend network delay that grows only logarithmically in V. This is the first algorithm to achieve such “superfast” performance. Furthermore, we show that this is the best utilitydelay tradeoff possible. This work demonstrates that the problem of maximizing throughput utility in a data network is fundamentally different than related problems of minimizing average power expenditure, as these latter problems cannot achieve such performance tradeoffs.
Distributed approaches for exploiting multiuser diversity in wireless networks
 IEEE Transactions on Information Theory
, 2006
"... In wireless fading channels, multiuser diversity can be exploited by scheduling users so that they transmit when their channel conditions are favorable. This leads to a sum throughput that increases with the number of users and, in certain cases, achieves capacity. However, such scheduling requires ..."
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Cited by 33 (2 self)
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In wireless fading channels, multiuser diversity can be exploited by scheduling users so that they transmit when their channel conditions are favorable. This leads to a sum throughput that increases with the number of users and, in certain cases, achieves capacity. However, such scheduling requires global knowledge of every user’s channel gain, which may be difficult to obtain in some situations. This paper addresses contentionbased protocols for exploiting multiuser diversity with only local channel knowledge. A variation of the classic ALOHA protocol is given in which users attempt to exploit multiuser diversity gains, but suffer contention losses due to the distributed channel knowledge. We characterize the growth rate of the sum throughput for this protocol in a backlogged system under both shortterm and longterm average power constraints. A simple “fixedrate ” system is shown to be asymptotically optimal and to achieve the same growth rate as in a system with a centralized scheduler. Moreover, asymptotically, the fraction of throughput lost due to contention is shown to be 1/e. Also, in a system with random arrivals and an infinite user population, a variation of this ALOHA protocol is shown to be stable for any total arrival rate, given that users can estimate the backlog. I.
Joint source coding and data rate adaptation for energy efficient wireless video streaming,” presented at the
 IEEE INT. PACKET VIDEO WORKSHOP
"... Abstract—Rapid growth in wireless networks is fueling demand for video services from mobile users. While the problem of transmitting video over unreliable channels has received some attention, the wireless network environment poses challenges such as transmission power management that have received ..."
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Cited by 33 (11 self)
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Abstract—Rapid growth in wireless networks is fueling demand for video services from mobile users. While the problem of transmitting video over unreliable channels has received some attention, the wireless network environment poses challenges such as transmission power management that have received little attention previously in connection with video. Transmission power management affects battery life in mobile devices, interference to other users, and network capacity. We consider energy efficient transmission of a video sequence under delay and quality constraints. The selection of source coding parameters is considered jointly with transmitter power and rate adaptation, and packet transmission scheduling. The goal is to transmit a video frame using the minimal required transmission energy under delay and quality constraints. Experimental results are presented that illustrate the advantages of the proposed approach. Index Terms—Energy efficiency, power and rate control, video streaming, wireless video. I.
Optimal Transmission Scheduling in Symmetric Communication Models with Intermittent Connectivity
, 2002
"... We consider a slotted system with N queues, and i.i.d. Bernoulli arrivals at each queue during each slot. Each queue is associated with a channel that changes between "on" and "off" states according to i.i.d. Bernoulli processes. We assume that the system has K identical transmit ..."
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Cited by 33 (2 self)
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We consider a slotted system with N queues, and i.i.d. Bernoulli arrivals at each queue during each slot. Each queue is associated with a channel that changes between "on" and "off" states according to i.i.d. Bernoulli processes. We assume that the system has K identical transmitters ("servers"). Each server, during each slot, can transmit up to C packets from each queue associated with an "on" channel. We show that a policy that assigns the servers to the longest queues whose channel is "on" minimizes the total queue size, as well as a broad class of other performance criteria. We provide several extensions, as well as some qualitative results for the limiting case where N is very large. Finally, we consider a "fluid" model under which fractional packets can be served, and subject to a constraint that at most C packets can be served in total from all of the N queues. We show that when K = N , there is an optimal policy which serves the queues so that the resulting vector of queue lengths is "Most Balanced."
Delayconstrained Scheduling: Power Efficiency, Filter Design, and Bounds
 IEEE INFOCOM, Hong Kong
, 2004
"... In this paper, packet scheduling with maximum delay constraints is considered with the objective to minimize average transmit power over Gaussian channels. The main emphasis is on deriving robust schedulers which do not rely on the knowledge of the source arrival process. Towards that end, we first ..."
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Cited by 32 (2 self)
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In this paper, packet scheduling with maximum delay constraints is considered with the objective to minimize average transmit power over Gaussian channels. The main emphasis is on deriving robust schedulers which do not rely on the knowledge of the source arrival process. Towards that end, we first show that all schedulers (robust or otherwise) which guarantee a maximum queuing delay for each packet are equivalent to a timevarying linear filter. Using the connection between filtering and scheduling, we study the design of optimal power minimizing robust schedulers. Two cases, motivated by filtering connection, are studied in detail. First, a timeinvariant robust scheduler is presented and its performance is completely characterized. Second, we present the optimal timevarying robust scheduler, and show that it has a very intuitive time waterfilling structure. We also present upper and lower bounds on the performance of powerminimizing schedulers as a function of delay constraints. The new results form an important step towards understanding of the packet timescale interactions between physical layer metric of power and network layer metric of delay.
Optimal Transmission Scheduling over a Fading Channel with Energy and Deadline Constraints
 IEEE Trans. Wireless Communications
, 2004
"... We seek to maximize the data throughput of an energy and time constrained transmitter sending data over a fading channel. The transmitter has a fixed amount of energy and a limited amount of time to send data. ..."
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Cited by 30 (0 self)
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We seek to maximize the data throughput of an energy and time constrained transmitter sending data over a fading channel. The transmitter has a fixed amount of energy and a limited amount of time to send data.
On the throughputdelay tradeoff in cellular multicast
 WirelessCom’05
, 2005
"... In this paper, we adopt a cross layer design approach for analyzing the throughputdelay tradeoff of the multicast channel in a single cell system. To illustrate the main ideas, we start with the single group case, i.e., pure multicast, where a common information stream is requested by all the users ..."
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Cited by 24 (0 self)
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In this paper, we adopt a cross layer design approach for analyzing the throughputdelay tradeoff of the multicast channel in a single cell system. To illustrate the main ideas, we start with the single group case, i.e., pure multicast, where a common information stream is requested by all the users. We consider three classes of scheduling algorithms with progressively increasing complexity. The first class strives for minimum complexity by resorting to a static scheduling strategy along with memoryless decoding. Our analysis for this class of scheduling algorithms reveals the existence of a static scheduling policy that achieves the optimal scaling law of the throughput at the expense of a delay that increases exponentially with the number of users. The second scheduling policy resorts to a higher complexity incremental redundancy encoding/decoding strategy to achieve a superior throughputdelay tradeoff. The third, and most complex, scheduling strategy benefits from the cooperation between the different users to minimize the delay while achieving the optimal scaling law of the throughput. In particular, the proposed cooperative multicast strategy is shown to simultaneously achieve the optimal scaling laws of both throughput and delay. Then, we generalize our scheduling algorithms to exploit the multigroup diversity available when different information streams are requested by different subsets of the user population. Finally, we discuss the effect of the potential gains of equipping the base station with multitransmit antennas and present simulation results that validate our theoretical claims. 1
Giannakis, “Energyefficient scheduling for wireless sensor networks
 IEEE Trans. on Commun
, 2005
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