TY - GEN
AU - Kothe, Nils
ID - 277
TI - Multilevel Netzwerk Spiele mit konstanten Entfernungen im Highspeed-Netzwerk
ER -
TY - JOUR
AB - Inter-datacenter transfers of non-interactive but timely large flows over a private (managed) network is an important problem faced by many cloud service providers. The considered flows are non-interactive because they do not explicitly target the end users. However, most of them must be performed on a timely basis and are associated with a deadline. We propose to schedule these flows by a centralized controller, which determines when to transmit each flow and which path to use. Two scheduling models are presented in this paper. In the first, the controller also determines the rate of each flow, while in the second bandwidth is assigned by the network according to the TCP rules. We develop scheduling algorithms for both models and compare their complexity and performance.
AU - Cohen, R.
AU - Polevoy, Gleb
ID - 17657
IS - 99
JF - Cloud Computing, IEEE Transactions on
KW - Approximation algorithms
KW - Approximation methods
KW - Bandwidth
KW - Cloud computing
KW - Routing
KW - Schedules
KW - Scheduling
SN - 2168-7161
TI - Inter-Datacenter Scheduling of Large Data Flows
VL - PP
ER -
TY - JOUR
AB - Abstract We study the problem of bandwidth allocation with multiple interferences. In this problem the input consists of a set of users and a set of base stations. Each user has a list of requests, each consisting of a base station, a frequency demand, and a profit that may be gained by scheduling this request. The goal is to find a maximum profit set of user requests S that satisfies the following conditions: (i) S contains at most one request per user, (ii) the frequency sets allotted to requests in S that correspond to the same base station are pairwise non-intersecting, and (iii) the QoS received by any user at any frequency is reasonable according to an interference model. In this paper we consider two variants of bandwidth allocation with multiple interferences. In the first each request specifies a demand that can be satisfied by any subset of frequencies that is large enough. In the second each request specifies a specific frequency interval. Furthermore, we consider two interference models, multiplicative and additive. We show that these problems are extremely hard to approximate if the interferences depend on both the interfered and the interfering base stations. On the other hand, we provide constant factor approximation algorithms for both variants of bandwidth allocation with multiple interferences for the case where the interferences depend only on the interfering base stations. We also consider a restrictive special case that is closely related to the Knapsack problem. We show that this special case is NP-hard and that it admits an FPTAS.
AU - Bar-Yehuda, Reuven
AU - Polevoy, Gleb
AU - Rawitz, Dror
ID - 17658
JF - Discrete Applied Mathematics
KW - Local ratio
SN - 0166-218X
TI - Bandwidth allocation in cellular networks with multiple interferences
VL - 194
ER -
TY - CONF
AB - Max-min fairness (MMF) is a widely known approach to a fair allocation of bandwidth to each of the users in a network. This allocation can be computed by uniformly raising the bandwidths of all users without violating capacity constraints. We consider an extension of these allocations by raising the bandwidth with arbitrary and not necessarily uniform time-depending velocities (allocation rates). These allocations are used in a game-theoretic context for routing choices, which we formalize in progressive filling games (PFGs).We present a variety of results for equilibria in PFGs. We show that these games possess pure Nash and strong equilibria. While computation in general is NP-hard, there are polynomial-time algorithms for prominent classes of Max-Min-Fair Games (MMFG), including the case when all users have the same source-destination pair. We characterize prices of anarchy and stability for pure Nash and strong equilibria in PFGs and MMFGs when players have different or the same source-destination pairs. In addition, we show that when a designer can adjust allocation rates, it is possible to design games with optimal strong equilibria. Some initial results on polynomial-time algorithms in this direction are also derived.
AU - Harks, Tobias
AU - Höfer, Martin
AU - Schewior, Kevin
AU - Skopalik, Alexander
ID - 370
T2 - Proceedings of the 33rd Annual IEEE International Conference on Computer Communications (INFOCOM'14)
TI - Routing Games with Progressive Filling
ER -
TY - GEN
AU - Pahl, David
ID - 373
TI - Reputationssysteme für zusammengesetzte Dienstleistungen
ER -
TY - CONF
AU - Polevoy, Gleb
AU - Trajanovski, Stojan
AU - de Weerdt, Mathijs M.
ID - 17659
KW - competition
KW - equilibrium
KW - market
KW - models
KW - shared effort games
KW - simulation
SN - 978-1-4503-2738-1
T2 - Proceedings of the 2014 International Conference on Autonomous Agents and Multi-agent Systems
TI - Nash Equilibria in Shared Effort Games
ER -
TY - CONF
AU - Polevoy, Gleb
AU - de Weerdt, Mathijs M.
ID - 17660
KW - dynamics
KW - emotion modeling
KW - negotiation
KW - network interaction
KW - shared effort game
SN - 978-1-4503-2738-1
T2 - Proceedings of the 2014 International Conference on Autonomous Agents and Multi-agent Systems
TI - Improving Human Interaction in Crowdsensing
ER -
TY - CONF
AU - King, Thomas C.
AU - Liu, Qingzhi
AU - Polevoy, Gleb
AU - de Weerdt, Mathijs
AU - Dignum, Virginia
AU - van Riemsdijk, M. Birna
AU - Warnier, Martijn
ID - 17661
KW - crowd-sensing
KW - crowdsourcing
KW - data aggregation
KW - game theory
KW - norms
KW - reciprocation
KW - self interested agents
KW - simulation
SN - 978-1-4503-2738-1
T2 - Proceedings of the 2014 International Conference on Autonomous Agents and Multi-agent Systems
TI - Request Driven Social Sensing
ER -
TY - JOUR
AU - Polevoy, Gleb
AU - Smorodinsky, Rann
AU - Tennenholtz, Moshe
ID - 17662
IS - 1
JF - ACM Trans. Econ. Comput.
KW - Competition
KW - efficiency
KW - equilibrium
KW - market
KW - social welfare
SN - 2167-8375
TI - Signaling Competition and Social Welfare
VL - 2
ER -
TY - CONF
AB - We introduce the concept of budget games. Players choose a set of tasks and each task has a certain demand on every resource in the game. Each resource has a budget. If the budget is not enough to satisfy the sum of all demands, it has to be shared between the tasks. We study strategic budget games, where the budget is shared proportionally. We also consider a variant in which the order of the strategic decisions influences the distribution of the budgets. The complexity of the optimal solution as well as existence, complexity and quality of equilibria are analysed. Finally, we show that the time an ordered budget game needs to convergence towards an equilibrium may be exponential.
AU - Drees, Maximilian
AU - Riechers, Sören
AU - Skopalik, Alexander
ED - Lavi, Ron
ID - 451
T2 - Proceedings of the 7th International Symposium on Algorithmic Game Theory (SAGT)
TI - Budget-restricted utility games with ordered strategic decisions
ER -
TY - CONF
AB - Today's networks, like the Internet, do not consist of one but a mixture of several interconnected networks. Each has individual qualities and hence the performance of a network node results from the networks' interplay.We introduce a new game theoretic model capturing the interplay between a high-speed backbone network and a low-speed general purpose network. In our model, n nodes are connected by a static network and each node can decide individually to become a gateway node. A gateway node pays a fixed price for its connection to the high-speed network, but can utilize the high-speed network to gain communication distance 0 to all other gateways. Communication distances in the low-speed network are given by the hop distances. The effective communication distance between any two nodes then is given by the shortest path, which is possibly improved by using gateways as shortcuts.Every node v has the objective to minimize its communication costs, given by the sum (SUM-game) or maximum (MAX-game) of the effective communication distances from v to all other nodes plus a fixed price \alpha > 0, if it decides to be a gateway. For both games and different ranges of \alpha, we study the existence of equilibria, the price of anarchy, and convergence properties of best-response dynamics.
AU - Abshoff, Sebastian
AU - Cord-Landwehr, Andreas
AU - Jung, Daniel
AU - Skopalik, Alexander
ED - Lavi, Ron
ID - 452
T2 - Proceedings of the 7th International Symposium on Algorithmic Game Theory (SAGT)
TI - Brief Announcement: A Model for Multilevel Network Games
ER -
TY - CONF
AB - In this paper we study the potential function in congestion games. We consider both games with non-decreasing cost functions as well as games with non-increasing utility functions. We show that the value of the potential function $\Phi(\sf s)$ of any outcome $\sf s$ of a congestion game approximates the optimum potential value $\Phi(\sf s^*)$ by a factor $\Psi_{\mathcal{F}}$ which only depends on the set of cost/utility functions $\mathcal{F}$, and an additive term which is bounded by the sum of the total possible improvements of the players in the outcome $\sf s$. The significance of this result is twofold. On the one hand it provides \emph{Price-of-Anarchy}-like results with respect to the potential function. On the other hand, we show that these approximations can be used to compute $(1+\varepsilon)\cdot\Psi_{\mathcal{F}}$-approximate pure Nash equilibria for congestion games with non-decreasing cost functions. For the special case of polynomial cost functions, this significantly improves the guarantees from Caragiannis et al. [FOCS 2011]. Moreover, our machinery provides the first guarantees for general latency functions.
AU - Feldotto, Matthias
AU - Gairing, Martin
AU - Skopalik, Alexander
ID - 453
T2 - Proceedings of the 10th International Conference on Web and Internet Economics (WINE)
TI - Bounding the Potential Function in Congestion Games and Approximate Pure Nash Equilibria
ER -
TY - CONF
AB - We study the existence of approximate pure Nash equilibria in weighted congestion games and develop techniques to obtain approximate potential functions that prove the existence of alpha-approximate pure Nash equilibria and the convergence of alpha-improvement steps. Specifically, we show how to obtain upper bounds for approximation factor alpha for a given class of cost functions. For example for concave cost functions the factor is at most 3/2, for quadratic cost functions it is at most 4/3, and for polynomial cost functions of maximal degree d it is at at most d + 1. For games with two players we obtain tight bounds which are as small as for example 1.054 in the case of quadratic cost functions.
AU - Hansknecht, Christoph
AU - Klimm, Max
AU - Skopalik, Alexander
ID - 455
T2 - Proceedings of the 17th. International Workshop on Approximation Algorithms for Combinatorial Optimization Problems (APPROX)
TI - Approximate pure Nash equilibria in weighted congestion games
ER -
TY - CONF
AB - We study the existence of approximate pure Nash equilibriain social context congestion games. For any given set of allowed costfunctions F, we provide a threshold value μ(F), and show that for theclass of social context congestion games with cost functions from F, α-Nash dynamics are guaranteed to converge to α-approximate pure Nashequilibrium if and only if α > μ(F).Interestingly, μ(F) is related and always upper bounded by Roughgarden’sanarchy value [19].
AU - Gairing, Martin
AU - Kotsialou, Grammateia
AU - Skopalik, Alexander
ID - 456
T2 - Proceedings of the 10th International Conference on Web and Internet Economics (WINE)
TI - Approximate pure Nash equilibria in Social Context Congestion Games
ER -
TY - CONF
AB - We discuss a technique to analyze complex infinitely repeated games using techniques from the fields of game theory and simulations. Our research is motivated by the analysis of electronic markets with thousands of participants and possibly complex strategic behavior. We consider an example of a global market of composed IT services to demonstrate the use of our simulation technique. We present our current work in this area and we want to discuss further approaches for the future.
AU - Feldotto, Matthias
AU - Skopalik, Alexander
ID - 462
T2 - Proceedings of the 4th International Conference on Simulation and Modeling Methodologies, Technologies and Applications (SIMULTECH 2014)
TI - A Simulation Framework for Analyzing Complex Infinitely Repeated Games
ER -
TY - CONF
AB - We consider a multilevel network game, where nodes can improvetheir communication costs by connecting to a high-speed network.The n nodes are connected by a static network and each node can decideindividually to become a gateway to the high-speed network. The goalof a node v is to minimize its private costs, i.e., the sum (SUM-game) ormaximum (MAX-game) of communication distances from v to all othernodes plus a fixed price α > 0 if it decides to be a gateway. Between gatewaysthe communication distance is 0, and gateways also improve othernodes’ distances by behaving as shortcuts. For the SUM-game, we showthat for α ≤ n − 1, the price of anarchy is Θ (n/√α) and in this rangeequilibria always exist. In range α ∈ (n−1, n(n−1)) the price of anarchyis Θ(√α), and for α ≥ n(n − 1) it is constant. For the MAX-game, weshow that the price of anarchy is either Θ (1 + n/√α), for α ≥ 1, orelse 1. Given a graph with girth of at least 4α, equilibria always exist.Concerning the dynamics, both games are not potential games. For theSUM-game, we even show that it is not weakly acyclic.
AU - Abshoff, Sebastian
AU - Cord-Landwehr, Andreas
AU - Jung, Daniel
AU - Skopalik, Alexander
ID - 395
T2 - Proceedings of the 10th International Conference on Web and Internet Economics (WINE)
TI - Multilevel Network Games
ER -
TY - CONF
AB - In this paper we present and analyze HSkip+, a self-stabilizing overlay network for nodes with arbitrary heterogeneous bandwidths. HSkip+ has the same topology as the Skip+ graph proposed by Jacob et al. [PODC 2009] but its self-stabilization mechanism significantly outperforms the self-stabilization mechanism proposed for Skip+. Also, the nodes are now ordered according to their bandwidths and not according to their identifiers. Various other solutions have already been proposed for overlay networks with heterogeneous bandwidths, but they are not self-stabilizing. In addition to HSkip+ being self-stabilizing, its performance is on par with the best previous bounds on the time and work for joining or leaving a network of peers of logarithmic diameter and degree and arbitrary bandwidths. Also, the dilation and congestion for routing messages is on par with the best previous bounds for such networks, so that HSkip+ combines the advantages of both worlds. Our theoretical investigations are backed by simulations demonstrating that HSkip+ is indeed performing much better than Skip+ and working correctly under high churn rates.
AU - Feldotto, Matthias
AU - Scheideler, Christian
AU - Graffi, Kalman
ID - 412
T2 - Proceedings of the 14th IEEE International Conference on Peer-to-Peer Computing (P2P)
TI - HSkip+: A Self-Stabilizing Overlay Network for Nodes with Heterogeneous Bandwidths
ER -
TY - JOUR
AB - In this paper, we define and study a new problem, referred to as the Dependent Unsplittable Flow Problem (D-UFP). We present and discuss this problem in the context of large-scale powerful (radar/camera) sensor networks, but we believe it has important applications on the admission of large flows in other networks as well. In order to optimize the selection of flows transmitted to the gateway, D-UFP takes into account possible dependencies between flows. We show that D-UFP is more difficult than NP-hard problems for which no good approximation is known. Then, we address two special cases of this problem: the case where all the sensors have a shared channel and the case where the sensors form a mesh and route to the gateway over a spanning tree.
AU - Cohen, R.
AU - Nudelman, I.
AU - Polevoy, Gleb
ID - 17663
IS - 5
JF - Networking, IEEE/ACM Transactions on
KW - Approximation algorithms
KW - Approximation methods
KW - Bandwidth
KW - Logic gates
KW - Radar
KW - Vectors
KW - Wireless sensor networks
KW - Dependent flow scheduling
KW - sensor networks
SN - 1063-6692
TI - On the Admission of Dependent Flows in Powerful Sensor Networks
VL - 21
ER -
TY - CONF
AU - Cohen, Reuven
AU - Nudelman, Ilia
AU - Polevoy, Gleb
ID - 17664
T2 - Infocom'2012, Orlando, Florida
TI - On the Admission of Dependent Flows in Powerful Sensor Networks
ER -
TY - CONF
AU - Bar-Yehuda, Reuven
AU - Polevoy, Gleb
AU - Rawitz, Dror
ID - 17665
T2 - DIALM-PODC
TI - Bandwidth allocation in cellular networks with multiple interferences
ER -