Results 11  20
of
1,356
AntNet: Distributed stigmergetic control for communications networks
 Journal of Artificial Intelligence Research
, 1998
"... This paper introduces AntNet, a novel approach to the adaptive learning of routing tables in communications networks. AntNet is a distributed, mobile agents based Monte Carlo system that was inspired by recent work on the ant colony metaphor for solving optimization problems. AntNet's agents concurr ..."
Abstract

Cited by 240 (30 self)
 Add to MetaCart
This paper introduces AntNet, a novel approach to the adaptive learning of routing tables in communications networks. AntNet is a distributed, mobile agents based Monte Carlo system that was inspired by recent work on the ant colony metaphor for solving optimization problems. AntNet's agents concurrently explore the network and exchange collected information. The communication among the agents is indirect and asynchronous, mediated by the network itself. This form of communication is typical of social insects and is called stigmergy. We compare our algorithm with six stateoftheart routing algorithms coming from the telecommunications and machine learning elds. The algorithms' performance is evaluated over a set of realistic testbeds. We run many experiments over real and arti cial IP datagram networks with increasing number of nodes and under several paradigmatic spatial and temporal tra c distributions. Results are very encouraging. AntNet showed superior performance under all the experimental conditions with respect to its competitors. We analyze the main characteristics of the algorithm and try to explain the reasons for its superiority. 1.
EnergyEfficient, CollisionFree Medium Access Control for Wireless Sensor Networks
, 2003
"... The trafficadaptive medium access protocol (TRAMA) is introduced for energyefficient collisionfree channel access in wireless sensor networks. TRAMA reduces energy consumption by ensuring that unicast and broadcast transmissions incur no collisions, and by allowing nodes to assume a lowpower, ..."
Abstract

Cited by 224 (3 self)
 Add to MetaCart
The trafficadaptive medium access protocol (TRAMA) is introduced for energyefficient collisionfree channel access in wireless sensor networks. TRAMA reduces energy consumption by ensuring that unicast and broadcast transmissions incur no collisions, and by allowing nodes to assume a lowpower, idle state whenever they are not transmitting or receiving.
The Stable Paths Problem and Interdomain Routing
 IEEE/ACM Transactions on Networking
, 2002
"... Abstract—Dynamic routing protocols such as RIP and OSPF essentially implement distributed algorithms for solving the shortest paths problem. The border gateway protocol (BGP) is currently the only interdomain routing protocol deployed in the Internet. BGP does not solve a shortest paths problem sinc ..."
Abstract

Cited by 211 (8 self)
 Add to MetaCart
Abstract—Dynamic routing protocols such as RIP and OSPF essentially implement distributed algorithms for solving the shortest paths problem. The border gateway protocol (BGP) is currently the only interdomain routing protocol deployed in the Internet. BGP does not solve a shortest paths problem since any interdomain protocol is required to allow policybased metrics to override distancebased metrics and enable autonomous systems to independently define their routing policies with little or no global coordination. It is then natural to ask if BGP can be viewed as a distributed algorithm for solving some fundamental problem. We introduce the stable paths problem and show that BGP can be viewed as a distributed algorithm for solving this problem. Unlike a shortest path tree, such a solution does not represent a global optimum, but rather an equilibrium point in which each node is assigned its local optimum. We study the stable paths problem using a derived structure called a dispute wheel, representing conflicting routing policies at various nodes. We show that if no dispute wheel can be constructed, then there exists a unique solution for the stable paths problem. We define the simple path vector protocol (SPVP), a distributed algorithm for solving the stable paths problem. SPVP is intended to capture the dynamic behavior of BGP at an abstract level. If SPVP converges, then the resulting state corresponds to a stable paths solution. If there is no solution, then SPVP always diverges. In fact, SPVP can even diverge when a solution exists. We show that SPVP will converge to the unique solution of an instance of the stable paths problem if no dispute wheel exists. Index Terms—BGP, Border Gateway Protocol, interdomain routing, internet routing, path vector protocols, stable routing.
Ondemand Multipath Distance Vector Routing in Ad Hoc Networks
 in Proceedings of IEEE International Conference on Network Protocols (ICNP
, 2001
"... We develop an ondemand, multipath distance vector protocol for mobile ad hoc networks. Specifically, we propose multipath extensions to a wellstudied single path routing protocol known as Ad hoc Ondemand Distance Vector (AODV). The resulting protocol is referred to as Ad hoc Ondemand Multipath Di ..."
Abstract

Cited by 210 (3 self)
 Add to MetaCart
We develop an ondemand, multipath distance vector protocol for mobile ad hoc networks. Specifically, we propose multipath extensions to a wellstudied single path routing protocol known as Ad hoc Ondemand Distance Vector (AODV). The resulting protocol is referred to as Ad hoc Ondemand Multipath Distance Vector (AOMDV). The protocol computes multiple loopfree and linkdisjoint paths. Loopfreedom is guaranteed by using a notion of "advertised hopcount." Linkdisjointness of multiple paths is achieved by using a particular property of flooding. Performance comparison of AOMDV with AODV using ns2 simulations shows that AOMDV is able to achieve a remarkable improvement in the endtoend delay  often more than a factor of two, and is also able to reduce routing overheads by about 20%. 1
An analysis of BGP convergence properties
 In SIGCOMM
"... The Border Gateway Protocol (BGP) is the de facto interdomain routing protocol used to exchange reachability information between Autonomous Systems in the global Internet. BGP is a pathvector protocol that allows each Autonomous System to override distancebased metrics with policybased metrics wh ..."
Abstract

Cited by 208 (14 self)
 Add to MetaCart
The Border Gateway Protocol (BGP) is the de facto interdomain routing protocol used to exchange reachability information between Autonomous Systems in the global Internet. BGP is a pathvector protocol that allows each Autonomous System to override distancebased metrics with policybased metrics when choosing best routes. Varadhan et al. [18] have shown that it is possible for a group of Autonomous Systems to independently define BGP policies that together lead to BGP protocol oscillations that never converge on a stable routing. One approach to addressing this problem is based on static analysis of routing policies to determine if they are safe. We explore the worstcase complexity for convergenceoriented static analysis of BGP routing policies. We present an abstract model of BGP and use it to define several global sanity conditions on routing policies that are related to BGP convergence/divergence. For each condition we show that the complexity of statically checking it is either NPcomplete or NPhard. 1
Efficient power control via pricing in wireless data networks
 IEEE Transactions on Communication
, 2000
"... A major challenge in operation of wireless communications systems is the efficient use of radio resources. One important component of radio resource management is power control, which has been studied extensively in the context of voice communications. With increasing demand for wireless data servic ..."
Abstract

Cited by 201 (6 self)
 Add to MetaCart
A major challenge in operation of wireless communications systems is the efficient use of radio resources. One important component of radio resource management is power control, which has been studied extensively in the context of voice communications. With increasing demand for wireless data services, it is necessary to establish power control algorithms for information sources other than voice. We present a power control solution for wireless data in the analytical setting of a game theoretic framework. In this context, the quality of service (QoS) a wireless terminal receives is referred to as the utility and distributed power control is a noncooperative power control game where users maximize their utility. The outcome of the game results in a Nash equilibrium that is ine#cient. We introduce pricing of transmit powers in order to obtain Pareto improvement of the noncooperative power control game, i.e. to obtain improvements in user utilities relative to the case with no pricing. Specifically, we consider a pricing function that is a linear function of the transmit power. The simplicity of the pricing function allows a distributed implementation where the price can be broadcast by the base station to all the terminals. We see that pricing is especially helpful in a heavily loaded system.
Endtoend congestion control schemes: Utility functions, random losses and ECN marks
 In Proceedings of IEEE Infocom
, 2000
"... We present a framework for designing endtoend congestion control schemes in a network where each user may have a different utility function and may experience noncongestionrelated losses. We first show that there exists an additive increasemultiplicative decrease scheme using only endtoend me ..."
Abstract

Cited by 178 (1 self)
 Add to MetaCart
We present a framework for designing endtoend congestion control schemes in a network where each user may have a different utility function and may experience noncongestionrelated losses. We first show that there exists an additive increasemultiplicative decrease scheme using only endtoend measurable losses such that a sociallyoptimal solution can be reached. We incorporate roundtrip delay in this model, and show that one can generalize observations regarding TCPtype congestion avoidance to more general window flow control schemes. We then consider explicit congestion notification (ECN) as an alternate mechanism (instead of losses) for signaling congestion and show that ECN marking levels can be designed to nearly eliminate losses in the network by choosing the marking level independently for each node in the network. While the ECN marking level at each node may depend on the number of flows through the node, the appropriate marking level can be estimated using only aggregate flow measurements, i.e., perflow measurements are not required. 1
A game theoretic framework for bandwidth allocation and pricing in broadband networks
 IEEE/ACM Trans. on Networking
, 2000
"... Abstract—In this paper, we present a game theoretic framework for bandwidth allocation for elastic services in highspeed networks. The framework is based on the idea of the Nash bargaining solution from cooperative game theory, which not only provides the rate settings of users that are Pareto opti ..."
Abstract

Cited by 176 (4 self)
 Add to MetaCart
Abstract—In this paper, we present a game theoretic framework for bandwidth allocation for elastic services in highspeed networks. The framework is based on the idea of the Nash bargaining solution from cooperative game theory, which not only provides the rate settings of users that are Pareto optimal from the point of view of the whole system, but are also consistent with the fairness axioms of game theory. We first consider the centralized problem and then show that this procedure can be decentralized so that greedy optimization by users yields the system optimal bandwidth allocations. We propose a distributed algorithm for implementing the optimal and fair bandwidth allocation and provide conditions for its convergence. The paper concludes with the pricing of elastic connections based on users ’ bandwidth requirements and users’ budget. We show that the above bargaining framework can be used to characterize a rate allocation and a pricing policy which takes into account users ’ budget in a fair way and such that the total network revenue is maximized. Index Terms—Bandwidth allocation, elastic traffic, game theory, Nash bargaining solution, pricing. I.
Selfish Routing and the Price of Anarchy
, 2005
"... Abstract Selfish routing is a classical mathematical model of how selfinterested users might route traffic through a congested network. The outcome of selfish routing is generally inefficient, in that it fails to optimize natural objective functions. The price of anarchy is a quantitative measure o ..."
Abstract

Cited by 175 (12 self)
 Add to MetaCart
Abstract Selfish routing is a classical mathematical model of how selfinterested users might route traffic through a congested network. The outcome of selfish routing is generally inefficient, in that it fails to optimize natural objective functions. The price of anarchy is a quantitative measure of this inefficiency. We survey recent work that analyzes the price of anarchy of selfish routing. We also describe related results on bounding the worstpossible severity of a phenomenon called Braess's Paradox, and on three techniques for reducing the price of anarchy of selfish routing. This survey concentrates on the contributions of the author's PhD thesis, but also discusses several more recent results in the area.
Statistical bandwidth sharing: a study of congestion at flow level
, 2001
"... In this paper we study the statistics of the realized throughput of elastic document transfers, accounting for the way network bandwidth is shared dynamically between the randomly varying number of concurrent flows. We first discuss the way TCP realizes statistical bandwidth sharing, illustrating es ..."
Abstract

Cited by 174 (17 self)
 Add to MetaCart
In this paper we study the statistics of the realized throughput of elastic document transfers, accounting for the way network bandwidth is shared dynamically between the randomly varying number of concurrent flows. We first discuss the way TCP realizes statistical bandwidth sharing, illustrating essential properties by means of packet level simulations. Mathematical flow level models based on the theory of stochastic networks are then proposed to explain the observed behavior. A notable result is that first order performance (e.g., mean throughput) is insensitive with respect both to the flow size distribution and the flow arrival process, as long as “sessions ” arrive according to a Poisson process. Perceived performance is shown to depend most significantly on whether demand at flow level is less than or greater than available capacity. The models provide a key to understanding the effectiveness of techniques for congestion management and service differentiation. 1.