Bandwidth problems in high-speed networks
TL;DR: This paper illustrates four bandwidth problems in high-speed networks, and describes several solutions to them, which are concerned with the ability to dynamically reconfigure a network in order to efficiently benefit from network resources.
Abstract: High-speed networks are capable of carrying many types of services such as voice, data, images, and video. These services have different requirements in terms of bandwidth, cell loss, delay, etc. The goal is to maximize the quality of service offered during periods of stress, as viewed by both the network provider and the customer. Many problems are created by these different requirements. This paper illustrates four bandwidth problems in high-speed networks, then describes several solutions to them. The first problem is topology design and bandwidth allocation, and it is concerned with the ability to dynamically reconfigure a network in order to efficiently benefit from network resources. The second problem is concerned with flow control and congestion avoidance. Bandwidth management (BWM) protocols are used to prevent congestion, essentially by accepting or refusing a new-arrival cell. The third problem, which is the most critical one, is bandwidth allocation, which is concerned with successful integration of link capacities through the different types of services. Given that a virtual path is a logical direct link, composed of a number of virtual circuits, between any two nodes, the last problem is concerned with how to assign bandwidth to each virtual path in the network, in order to optimize performance for all users. This paper may be a good guide to researchers concerned with high-speed networks in general.
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01 Jan 1991
TL;DR: The integration of adaptive call admission control and adaptive link capacity control yields an efficient ATM traffic control system suitable for multimedia communication services with unknown traffic characteristics.
Abstract: An adaptive call admission control using neural networks was recently proposed for asynchronous transfer mode (ATM) communications networks. The author proposes adaptive link capacity control using neural networks. Neural networks are trained to estimate the call loss rate from link capacity and observed traffic, and link capacity assignment is optimized by a random optimization method according to the estimated call loss rate. The integration of adaptive call admission control and adaptive link capacity control yields an efficient ATM traffic control system suitable for multimedia communication services with unknown traffic characteristics. Computer simulation results using a simple network model are also given to evaluate the accuracy and efficiency of the proposed method. >
77 citations
Patent•
03 Apr 2002TL;DR: A method and apparatus for token distribution include providing one or more nodes of a plurality of network nodes with a token machine that includes counters associated with each other network nodes having a token machines as discussed by the authors.
Abstract: A method and apparatus for token distribution include providing one or more nodes of a plurality of network nodes with a token machine that includes counters associated with each of other network nodes having a token machine. Each time a token possessing network node implicitly or explicitly passes the token to another network node having a token machine, counter values of each of the counters associated with each node having a token machine are adjusted. When a token is passed, the counter value of the receiving node is adjusted based, at least in part, on an initial token interval value, and counter values associated with other nodes are adjusted toward a threshold value. The decision as to where the token is passed may be based, at least in part, on the value of a counter and/or an assigned counter priority level. The system or method also may include priority slots in which the token is unconditionally passed to a node assigned the priority slot, and an ARQ scheme for acknowledgment of transferred information.
28 citations
19 May 2002
TL;DR: This paper investigates the capacity assignment problem in Bluetooth scatternets and develops an optimal algorithm which is similar to the well-known flow deviation algorithm and that calls for solving a maximum-weight matching problem at each iteration.
Abstract: Bluetooth enables portable electronic devices to communicate wirelessly via short-range ad-hoc networks. Initially Bluetooth will be used as a replacement for point-to-(multi)point cables. However, in due course, there will be a need for forming multihop ad-hoc networks over Bluetooth, referred to as scatternets. This paper investigates the capacity assignment problem in Bluetooth scatternets. The problem arises primarily from the special characteristics of the network and its solution requires new protocols. We formulate it as a problem of minimizing a convex function over a polytope contained in the matching polytope. Then, we develop an optimal algorithm which is similar to the well-known flow deviation algorithm and that calls for solving a maximum-weight matching problem at each iteration. Finally, a heuristic algorithm with a relatively low complexity is developed.
18 citations
Cites background from "Bandwidth problems in high-speed ne..."
...Most models of capacity assignment in communication networks deal mainly with static networks in which a cost is associated with each level of link capacity (see [3] and [22] for a review of models and algorithms)....
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06 Mar 2006
TL;DR: The authors propose a subsystem called Protocol Engineering and Technology unit – Agent-based Subsystem for Multimedia Communications (PET-ASMAC) at the client side, which is an intelligent multimedia communication assistant to facilitate multimedia presentation to Internet users.
Abstract: There are several issues in multimedia communications, such as resource allocation, quality-of-service (QoS) routing, synchronisation, playout compensation and so on, which affect the continuous and smooth running of a multimedia application. The Internet demands the design of flexible and adaptable multimedia services so as to offer better quality presentations to the user. In this context, agent technology is emerging as a promising solution to provide flexible and adaptable services in distributed environments. The authors propose a subsystem called Protocol Engineering and Technology unit – Agent-based Subsystem for Multimedia Communications (PET-ASMAC) at the client side, which is an intelligent multimedia communication assistant to facilitate multimedia presentation to Internet users. The PETASMAC comprises a set of static and mobile agents, which perform certain autonomous tasks (QoS routing, resource allocation, synchronisation and playout) that satisfy the full-service requirements of an application, and coordinate with each other to provide smooth and continuous multimedia presentations. PET-ASMAC is simulated in several network scenarios to evaluate its effectiveness. The subsystem considers presentations from a single server to a client. However, it can be easily extended for multipoint-to-point communication. The results are encouraging and the observed benefits of the agent technology in multimedia communications are flexibility, adaptability, customisability, maintainability, re-usability and support to component-based software engineering.
16 citations
07 Nov 2002
TL;DR: This paper considers joint problems of adaptive bandwidth reservation and link rearrangement (rerouting) for multimedia traffic under the event of congestion/failures of link, and proposes a mobile agent based approach to achieve these objectives.
Abstract: The bandwidth reservation for multimedia traffic poses technical challenges due to the bursty and delay sensitive nature of applications. The objectives of bandwidth reservation schemes are: optimize network utilization, and minimize the packet losses and delays. The growth of multimedia services on the Internet and the possible discovery of programmable networks has made us investigate new techniques for resolving bandwidth issues in multimedia communication. Mobile agent technology seems to be a promising solution for network management and QoS control. In this paper, we consider joint problems of adaptive bandwidth reservation and link rearrangement (rerouting) for multimedia traffic under the event of congestion/failures of link, and propose a mobile agent based approach to achieve these objectives. The scheme is simulated using a multimedia traffic model. Simulation results show that the use of agents increases the network utilization, acceptance ratio of applications, flexibility and efficiency of bandwidth reservation. The flexibility in using agent technology is that the policies can be changed and implemented easily by encoding in the agents.
16 citations
References
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Book•
03 Mar 1993
TL;DR: The book is a solid reference for professionals as well as a useful text for students in the fields of operations research, management science, industrial engineering, applied mathematics, and also in engineering disciplines that deal with analytical optimization techniques.
Abstract: COMPREHENSIVE COVERAGE OF NONLINEAR PROGRAMMING THEORY AND ALGORITHMS, THOROUGHLY REVISED AND EXPANDED"Nonlinear Programming: Theory and Algorithms"--now in an extensively updated Third Edition--addresses the problem of optimizing an objective function in the presence of equality and inequality constraints. Many realistic problems cannot be adequately represented as a linear program owing to the nature of the nonlinearity of the objective function and/or the nonlinearity of any constraints. The "Third Edition" begins with a general introduction to nonlinear programming with illustrative examples and guidelines for model construction.Concentration on the three major parts of nonlinear programming is provided: Convex analysis with discussion of topological properties of convex sets, separation and support of convex sets, polyhedral sets, extreme points and extreme directions of polyhedral sets, and linear programmingOptimality conditions and duality with coverage of the nature, interpretation, and value of the classical Fritz John (FJ) and the Karush-Kuhn-Tucker (KKT) optimality conditions; the interrelationships between various proposed constraint qualifications; and Lagrangian duality and saddle point optimality conditionsAlgorithms and their convergence, with a presentation of algorithms for solving both unconstrained and constrained nonlinear programming problemsImportant features of the "Third Edition" include: New topics such as second interior point methods, nonconvex optimization, nondifferentiable optimization, and moreUpdated discussion and new applications in each chapterDetailed numerical examples and graphical illustrationsEssential coverage of modeling and formulating nonlinear programsSimple numerical problemsAdvanced theoretical exercisesThe book is a solid reference for professionals as well as a useful text for students in the fields of operations research, management science, industrial engineering, applied mathematics, and also in engineering disciplines that deal with analytical optimization techniques. The logical and self-contained format uniquely covers nonlinear programming techniques with a great depth of information and an abundance of valuable examples and illustrations that showcase the most current advances in nonlinear problems.
6,259 citations
IBM1
TL;DR: Worst-case bounds on delay and backlog are derived for leaky bucket constrained sessions in arbitrary topology networks of generalized processor sharing (GPS) servers and the effectiveness of PGPS in guaranteeing worst-case session delay is demonstrated under certain assignments.
Abstract: Worst-case bounds on delay and backlog are derived for leaky bucket constrained sessions in arbitrary topology networks of generalized processor sharing (GPS) servers. The inherent flexibility of the service discipline is exploited to analyze broad classes of networks. When only a subset of the sessions are leaky bucket constrained, we give succinct per-session bounds that are independent of the behavior of the other sessions and also of the network topology. However, these bounds are only shown to hold for each session that is guaranteed a backlog clearing rate that exceeds the token arrival rate of its leaky bucket. A much broader class of networks, called consistent relative session treatment (CRST) networks is analyzed for the case in which all of the sessions are leaky bucket constrained. First, an algorithm is presented that characterizes the internal traffic in terms of average rate and burstiness, and it is shown that all CRST networks are stable. Next, a method is presented that yields bounds on session delay and backlog given this internal traffic characterization. The links of a route are treated collectively, yielding tighter bounds than those that result from adding the worst-case delays (backlogs) at each of the links in the route. The bounds on delay and backlog for each session are efficiently computed from a universal service curve, and it is shown that these bounds are achieved by "staggered" greedy regimes when an independent sessions relaxation holds. Propagation delay is also incorporated into the model. Finally, the analysis of arbitrary topology GPS networks is related to Packet GPS networks (PGPS). The PGPS scheme was first proposed by Demers, Shenker and Keshav (1991) under the name of weighted fair queueing. For small packet sizes, the behavior of the two schemes is seen to be virtually identical, and the effectiveness of PGPS in guaranteeing worst-case session delay is demonstrated under certain assignments. >
3,967 citations
01 May 1992
TL;DR: The authors propose the use of a packet service discipline at the nodes of the network that is based on a multiplex scheme called generalized processor sharing (GPS) that is combined with leaky bucket rate admission control to provide flexible, efficient and fair use of the links.
Abstract: Worst-case bounds on delay and backlog are derived for leaky bucket constrained sessions in arbitrary topology networks of generalized processor sharing servers. When only a subset of the sessions are leaky bucket constrained succinct per-session bounds that are independent of the behavior of the other sessions and also of the network topology are given. However, these bounds are only shown to hold for each session that is guaranteed a backlog clearing rate that exceeds the token arrival rate of its leaky bucket. When all of the sessions are leaky bucket constrained, a much larger class of networks called consistent relative session treatment networks is analyzed. The session i route is treated as a whole, yielding tighter bounds than those that result from adding the worst-case delays (backlogs) at each of the servers in the route. The bounds on delay and backlog for each session are computed and shown to be achieved by staggered regimes when an independent sessions relaxation holds. Propagation delay is also incorporated into the model. >
1,348 citations
TL;DR: It is argued that controlled link-sharing is an essential component that can provide gateways with the flexibility to accommodate emerging applications and network protocols.
Abstract: Discusses the use of link-sharing mechanisms in packet networks and presents algorithms for hierarchical link-sharing. Hierarchical link-sharing allows multiple agencies, protocol families, or traffic types to share the bandwidth on a link in a controlled fashion. Link-sharing and real-time services both require resource management mechanisms at the gateway. Rather than requiring a gateway to implement separate mechanisms for link-sharing and real-time services, the approach in the paper is to view link-sharing and real-time service requirements as simultaneous, and in some respect complementary, constraints at a gateway that can be implemented with a unified set of mechanisms. While it is not possible to completely predict the requirements that might evolve in the Internet over the next decade, the authors argue that controlled link-sharing is an essential component that can provide gateways with the flexibility to accommodate emerging applications and network protocols. >
1,181 citations
PARC1
TL;DR: A new algorithm is described, VirtualClock, for data traffic control in high-speed networks that maintains the statistical multiplexing flexibility of pocket switching while ensuring each data flow its reserved average throughput rate at the same time.
Abstract: One of the challenging research issues in building high-speed packet-switched networks is how to control the transmission rate of statistical data flows. This paper describes a new traffic control algorithm, VirtualClock, for high-speed network applications. VirtualClock monitors the average transmission rate of statistical data flows and provides every flow with guaranteed throughput and low queueing delay. It provides firewall protection among individual flows, as in a TDM system, while retaining the statistical multiplexing advantages of packet switching. Simulation results show that the VirtualClock algorithm meets all its design goals.
706 citations