Showing papers on "Dynamic bandwidth allocation published in 2002"

IPACT a dynamic protocol for an Ethernet PON (EPON)

Abstract: We investigate design issues for access networks based on passive optical network technology. A PON based on polling, with data encapsulated in Ethernet frames, possesses many desirable qualities, such as dynamic bandwidth distribution, use of a single downstream and a single upstream wavelength, ability to provision a fractional wavelength capacity to each user, and ease of adding a new user. To support dynamic bandwidth distribution, we propose an interleaved polling algorithm called IPACT. We also suggest a scheme for in-band signaling that allows using a single wavelength for both downstream data and control message transmission. To obtain realistic simulation results, we generated synthetic traffic that exhibits the properties of self-similarity and long-range dependence. We then analyzed the network performance under varying offered loads.

Interleaved Polling with Adaptive Cycle Time (IPACT): A Dynamic Bandwidth Distribution Scheme in an Optical Access Network

Abstract: While in recent years backbone bandwidth has experienced substantial growth, little has changed in the access network. “Last mile” still remains the bottleneck between a high capacity LAN or home network and the backbone. Passive optical network (PON) is a technology viewed by many as an attractive solution to this problem. In this study, we discuss and evaluate design issues for PON access networks. Specifically, to drive the cost of an access network down, it is very important to have an efficient, scalable solution. We believe that a PON based on polling, with data encapsulated in Ethernet frames, possesses the best qualities, such as dynamic bandwidth distribution, use of a single downstream and a single upstream wavelength, ability to provision a fractional wavelength capacity to each user, and ease of adding a new user. To support dynamic bandwidth distribution, we propose an interleaved polling algorithm. We then suggest a scheme for in-band signaling that allows using a single wavelength for both downstream data and control message transmission. To obtain realistic simulation results, we generated synthetic traffic that exhibits the properties of self-similarity and long-range dependence. We then analyzed the network performance and its effect on various types of traffic, e.g., best-effort data traffic, VBR video traffic and CBR streams.

Revenue-maximizing pricing and capacity expansion in a many-users regime

Abstract: We consider a network where each user is charged a fixed price per unit of bandwidth used, but where there is no congestion-dependent pricing. However, the transmission rate of each user is assumed to be a function of network congestion (like TCP), and the price per unit bandwidth. We are interested in answering the following question: how should the network choose the price to maximize its overall revenue? To obtain a tractable solution, we consider a single link accessed by many users where the capacity is increased in proportion to the number of users. We show the following result: as the number of users increases, the optimal price per unit bandwidth charged by the service provider may increase or decrease depending upon the bandwidth of the link. However, for all values of the link capacity, the service provider's revenue per unit bandwidth increases and the overall performance of each user (measured in terms of a function of its throughput, the network congestion and the cost incurred by the user for bandwidth usage) improves. Since the revenue per unit bandwidth increases, it provides an incentive for the service provider to increase the available bandwidth in proportion to the number of users.

A QoS architecture for the MAC protocol of IEEE 802.16 BWA system

Abstract: Providing quality of service (QoS) guarantees for heterogeneous classes of traffic with different QoS requirements in fixed broadband wireless access (BWA) system is a very important and challenging problem Although IEEE 80216 MAC protocols have been proposed to support QoS guarantees for various kinds of applications, they do not suggest how to schedule traffic to fulfill QoS requirements In order to provide different levels of QoS guarantees for various applications while still achieving high system utilization, a QoS architecture should be integrated into the MAC protocol We first provide a background on the IEEE 80216 BWA system, we then propose an efficient QoS architecture, based on priority scheduling and dynamic bandwidth allocation, to provide QoS guarantees for the BWA system and propose an efficient scheduling strategy for schedulers in the architecture

System and method for providing bandwidth management for VPNs

Abstract: A method and system for controlling the bandwidths of data traffic over virtual private networks are provided. The method includes classifying the data traffic for the virtual private network into different flows, monitoring a current bandwidth usage by at least one of the flows, comparing the current bandwidth usage with a predetermined threshold for the flow, and performing a bandwidth control operation for the flow if the current bandwidth usage exceeds the predetermined threshold for that flow.

QoS control middleware in integrated network, QoS control method, and the program for the same

Abstract: An integrated QoS control system is provided that transmits, in real time, the stream data between a bandwidth-guaranteed network and a bandwidth-not-guaranteed network. The QoS manager 102 records the remaining bandwidth of the bandwidth-guaranteed network 2 captured by the remaining bandwidth table capturer 103 and the remaining bandwidth of the bandwidth-not-guaranteed network 1 calculated with traffic information notified by the network status monitor 107 on the use bandwidth registration table 104 (for comprehensively managing the bandwidth of an integrated network). The Qos manager 102 converts a QoS parameter received via the QoS request receiver 106 into a traffic parameter and controllably adapts the value of the traffic parameter to a service quality required by the application 109.

Adaptive allocation of last-hop bandwidth based on monitoring of end-to-end throughput

Abstract: An improved method and system for optimizing the allocation of bandwidth within a network system is presented. When a client device is engaged in communication with a remote computing device, an access point measures the throughput of the connection between the client device and the network. If the throughput is less than the amount of bandwidth reserved for usage by the client device, the access point adjusts the amount of bandwidth allocated for the client device to an amount equivalent to the measured throughput multiplied by an error variance factor. This process is then repeated periodically for the duration of the communication between the client device and the remote computing device in order to continually adapt the bandwidth allocation of the client device. Optionally, the method and system can be also deployed in client devices instead of the access point

Distributed weighted fair queuing in 802.11 wireless LAN

Abstract: With weighted fair queuing, the link's bandwidth is distributed among competing flows proportionally to their weights. In this paper we propose an extension of the DCF function of IEEE 802.11 to provide weighted fair queuing in wireless LAN. Simulation results show that the proposed scheme is able to provide the desired bandwidth distribution independent of the flows' aggressiveness and their willingness to transmit. Backwards compatibility is provided such that legacy IEEE 802.11 terminals receive a bandwidth corresponding to the default weight.

ABwE :A Practical Approach to Available Bandwidth Estimation

Abstract: We report on a new tool developed for monitoring available bandwidth in the range from several Mbps to 1000 Mbps. The tool is based on the packet pair dispersion technique . It has been in experimental use at SLAC for several months and it has been demonstrated at iGrid2002 and SC2002. It can b e used for detecting bandwidth changes caused by routing or congestions. We have studied the influence of cross traffic and the behavior of routers on the delay of the probing packets . The paper presents part of these analyses together with results from monitoring of 12 paths in US, Japan and in Europe. Index Terms—available bandwidth, dispersion technique, high- throughput, measurement tools, monitoring, networks, tuning, TCP.

Dynamic bandwidth allocation for multiple access communication using session queues

Abstract: A technique for providing high speed data service over standard wireless connections via an unique integration of protocols and existing cellular signaling, such as is available with Code Division Multiple Access (CDMA) type systems through more efficient allocation of access to CDMA channels. For example, when more users exist than channels, the invention determines a set of probabilities for which users will require channel access at which times, and dynamically assigns channel resources accordingly. Channel resources are allocated according to a buffer monitoring scheme provided on forward and reverse links between a base station and multiple subscriber units. Each buffer is monitored over time for threshold levels of data to be transmitted in that buffer. For each buffer, a probability is calculated that indicates how often the specific buffer will need to transmit data and how much data will be transmitted. This probability takes into account the arrival rates of data into the buffer, as well as which thresholds within the buffer are exceeded, as well as which resources in the form of channels are already allocated to the subscriber unit.

Implicit shared bandwidth protection for fast reroute

Abstract: A virtual overlay backup network is established to provide Fast Reroute capability with guaranteed bandwidth protection to a network that employs end-to-end circuits such as label switched paths (LSPs). In some implementations, backup bandwidth is allocated from an available backup bandwidth pool, as defined herein, available on each link. Complete bandwidth protection may be provided rapidly upon detection of a failure while available backup bandwidth is shared between independent failures. In one embodiment, this is accomplished by provisioning backup tunnels to protect all links and nodes, wherein total available backup bandwidth on any link is not exceeded by the requirements of backup tunnels protecting any single node but backup tunnels protecting different nodes may share bandwidth.

Service overlay networks: SLAs, QoS and bandwidth provisioning

Abstract: We advocate the notion of service overlay network (SON) as an effective means to address some of the issues, in particular end-to-end QoS, plaguing the current Internet, and to facilitate the creation and deployment of value-added Internet services such as VoIP, video-on-demand, and other emerging QoS-sensitive services. A SON purchases bandwidth with certain QoS guarantees from individual network domains via a bilateral service level agreement (SLA) to build a logical end-to-end service delivery infrastructure on top of existing data transport networks. Via a service contract, users directly pay the SON provider for using the value-added services provided by the SON. We study the bandwidth provisioning problem for a service overlay network which is critical to the cost recovery in deploying and operating value-added services over the SON. We mathematically formulate the bandwidth provisioning problem, taking into account various factors such as SLA, service QoS, traffic demand distributions, and bandwidth costs. Analytical models and approximate solutions are developed for both static and dynamic bandwidth provisioning. Numerical studies are also performed to illustrate the properties of the proposed solutions and demonstrate the effect of traffic demand distributions and bandwidth costs on the bandwidth provisioning of a SON.

Communication using multiple wireless interfaces

Abstract: With the emergence of different wireless technologies, a mobile terminal equipped with multiple interfaces can achieve a much higher bandwidth by aggregating the bandwidth offered by the individual networks. In this paper, we present a system based on Mobile IP that achieves the above objective. We discuss in detail the architectural requirements and algorithms that are needed to support the system.

Distributed information management schemes for dynamic allocation and de-allocation of bandwidth

Abstract: The invention is a novel and efficient distributed control scheme for dynamic allocation and de-allocation of bandwidth. The scheme can be applied to MPLS or MPλS networks where bandwidth guaranteed connections (A-> D, C-> D, B-> D) (either protected against single link or node (A, B, C or D) failure, unprotected or pre-emptable) need be established and released in a on-line fashion. It can be implemented as a part of the G-MPLS control framework. It achieves near optimal bandwidth sharing with only partial (aggregated) information, fast path determination and low processing and signaling overhead. Further, it can allocate and de-allocate bandwidth effectively as a request arrives, avoiding the need for complex optimization operations through e.g., network reconfiguration.

QoS extension to BGP

Abstract: To enable the end-to-end quality of service (QoS) guarantees in the Internet, based on the border gateway protocol (BGP), inter-domain QoS advertising and routing are important. However, little research has been done in this area so far. Two major challenges, scalability and heterogeneity, make the QoS extension to BGP difficult. Two existing approaches, link capacity routing (LCR) and available bandwidth routing (ABR), address QoS advertising and routing in BGP with respect to the bandwidth metric, but neither of them can solve the two challenges well. We extend BGP to advertise bandwidth information, but, instead of using link capacities or instantaneous available bandwidth values, a novel QoS metric, available bandwidth index (ABI), is defined and used to perform bandwidth advertising and routing. The two major contributions of ABI are: (1) ABI dynamically abstracts available bandwidth into a probability interval, therefore, it is very flexible to represent heterogenous and dynamic bandwidth values; (2) by capturing the statistical property of the detailed available bandwidth distribution, ABI is so efficient that it can highly decrease the message overhead in routing, thereby making the QoS advertising and routing very scalable. Our extensive simulations confirm both contributions of the ABI extension to BGP very well.

Dynamic bandwidth allocation with fair scheduling for WCDMA systems

Abstract: Dynamic bandwidth allocation (DBA) will play an important role in future broadband wireless networks, including the 3G and 4G WCDMA systems. A code-division generalized processor sharing (CDGPS) fair scheduling DBA scheme is proposed for WCDMA systems. The scheme exploits the capability of the WCDMA physical layer, reduces the computational complexity in the link layer, and allows channel rates to be dynamically and fairly scheduled in response to the variation of traffic rates. Deterministic delay bounds for heterogeneous packet traffic are derived. Simulation results show that the proposed CDGPS scheme is effective in supporting differentiated QoS, while achieving efficient utilization of radio resources.

Dynamic bandwidth allocation in ad hoc wireless piconets

Abstract: One of a number, n, of slave devices is selected for express or implicit polling by a master device in a communication system that transmits during individual ones of a number of sequentially occurring time slots. This is done by assigning a corresponding priority level to each slave device, wherein at least two slave devices are assigned different corresponding priority levels. A corresponding count parameter and a corresponding initial count value are assigned to each of the slave devices. For each of the slave devices, the corresponding count parameter is initialized to the corresponding initial count value. For each successive time slot, each of the count parameters is adjusted (e.g., by decrementing). A highest priority slave device whose corresponding count parameter has reached or passed a predetermined value is selected for polling.

Bandwidth updating method and bandwidth updating apparatus

Abstract: In a communications system in which a plurality of subscriber apparatuses and a station apparatus are connected to the same transmission channel for bidirectional communication, a bandwidth allocated in a direction from subscriber apparatuses to a station apparatus is dynamically updated. More specifically, a bandwidth usage rate is calculated from a bandwidth allocated in a updating period and a bandwidth actually used in the updating period. A bandwidth to be allocated in a subsequent period is determined based on the bandwidth usage rate thus calculated. With this construction, the station apparatus is capable of allocating the bandwidth required by the subscriber apparatuses or subscriber terminal apparatuses so that the bandwidth is efficiently used.

Efficient traffic prediction scheme for real-time VBR MPEG video transmission over high-speed networks

Abstract: The efficient transportation of real-time variable bit rate (VBR) video traffic in high-speed networks is currently an active area of research. The capability to predict VBR video traffic can significantly improve the effectiveness of numerous management tasks, including dynamic bandwidth allocation and congestion control. This paper proposes an adaptive traffic prediction method for VBR MPEG videos, a major multimedia application. Rapid traffic variations due to scene changes are analyzed, then a prediction scheme using the identification of scene changes related to I and P frames is presented. For predicting multiplexed MPEG traffic, a prediction interval is derived that represents a highly correlated traffic sequence. In addition, to reduce the prediction error, a less fluctuating signal instead of the original multiplexed traffic is used as the input for the predictor. Simulation results show that the proposed method is able to predict the original traffic more accurately than the conventional LMS method.

System and method for scheduling traffic for different classes of service

Abstract: A system and method for maximum utilization of bandwidth of a resource incrementally adjusts in real time the allocated bandwidth per source queue per class of service based at least in part on the current status of a destination virtual output queue fill level. By varying the permissible bandwidth incrementally not only is the available bandwidth utilized optimally but also a desired class of service is maintained.

Utility-oriented adaptive QoS and bandwidth allocation in wireless networks

Abstract: In this paper we propose a general utility-oriented adaptive quality of service (QoS) model for wireless networks and establish a framework for formulating the bandwidth allocation problem for users with time-varying links. For slow link variations, it is inadequate to only employ low-level adaptive mechanisms at the symbol or packet level, such as error correction coding or swapping packet transmission opportunities. To improve bandwidth utilization and satisfy users' QoS requirements, high-level adaptive mechanisms working at larger time scale are needed. We propose an adaptive bandwidth allocation scheme, which is capable of providing QoS guarantees, ensuring long-term fairness, and achieving high bandwidth utilization. A finite-state Markov channel model (FSMC) is used to model wireless links.

Estimating Available Bandwidth Using Packet Pair Probing

Abstract: : The packet pair mechanism has been shown to be a reliable method to measure the bottle-neck link bandwidth of a network path. However, the use of packet pairs to measure available bandwidth has had more mixed results. In this paper, we study how packet pairs and packet trains can be used to estimate the available bandwidth on a network path. As a starting point for our study, we construct the gap model, a simple model that captures the relationship between the competing traffic and the input and output packet pair gap for a single hop network. We validate the model using measurements on a testbed. The gap model shows that the initial probing gap is a critical parameter when using packet pairs to estimate available bandwidth. Based on this insight, we propose a new technique to measure the available bandwidth -- the Initial Gap Increasing (IGI) algorithm, which experimentally determines the best initial gap for measuring available bandwidth. Our experiments show that measurements that take 4-6 round trip times allow us to estimate the available bandwidth to within about 10%.

Method for dynamically allocating bandwidth in ATM passive optical network

Abstract: The present invention relates to a method for dynamically allocating bandwidth under a media access control (MAC) protocol between an optical line termination (OLT) and a group including a plurality of optical network units (ONUs) in an ATM-PON. In order to meet quality of service (QoS) requirement, the dynamic bandwidth allocation method is capable of determining bandwidth to be allocated to each of the ONUs on the basis of information about traffic indicators of connections established to each of the ONUs and about the number of non-real time cells waiting in each of the ONUs, resulting in an enhancement in utilization efficiency of an upstream transmission channel and enabling an effective transmission.

Overcoming neighborhood capture in wireless LANs

Abstract: A method is disclosed for addressing the problem of neighborhood capture, which arises in a multiple-cell wireless LAN with fewer channels available than the number of cells. Channel selection in WLAN networks must be accompanied by dynamic bandwidth allocation in order to avoid interference between co-channel cells. CSMA-type MAC protocols provide dynamic bandwidth allocation in a distributed manner, obviating the need for a central controller. With such protocols, time-overlapped transmissions by stations in non-interfering co-channel cells cooperate to capture the channel for long time periods. The result is deleterious to QoS because of the ensuing access delays in other co-channel cells. According to this invention, the neighborhood capture problem is mitigated through Global Channel Release. The method provides for all stations to release the channel at pre-specified times, ideally regularly-spaced. All co-channel cells are thus given an equal opportunity to contend for the channel. The method eliminates unfairness due to the synergy of the cells in a reuse group in capturing the channel, at the expense of co-channel cells outside that group. The method also provides for the synchronization of stations in all cells. Synchronization occurs constantly, starting as stations power up. Safeguards are provided for the elimination of inequities by distributing traffic loads equally across both cells and reuse groups for all stations to have the same success rate in seizing the channel.

Dynamic bandwidth reallocation

Abstract: Bandwidth allocated between the traffic classes of a network path is dynamically reallocated when one or more traffic classes have insufficient available bandwidth to support a service request for the traffic classes, wherein the reallocation occurs without modifying the traffic class bandwidth allocations enforced by router mechanisms. A provisioning system maintains an available bandwidth indication for each traffic class, which indications are decremented as a service request is admitted to the path. If a requested traffic class has insufficient available bandwidth to support a request, one or more other traffic classes can loan bandwidth to the requested traffic class by decrementing the available bandwidth indicators for the one or more other traffic classes in the amount of the insufficiency, thereby indicating that less bandwidth is available in these classes for future requests. The provisioning system also maintains an indication of the amount of bandwidth each traffic class loans to the other traffic classes.

Reservation-based media access controller and reservation-based optical network

Abstract: A method and apparatus for reserving bandwidth in a network includes a series of elements. A demand matrix is calculated, for bandwidth requirements based upon communication needs among a plurality of nodes on the network. An integer number of time slots is provided, aligned around the network. Bandwidth is reserved for node-to-node communication based upon the demand matrix. The reserving of bandwidth reserves bandwidth between two nodes based upon time-slot alignment. Transmission is scheduled between the two nodes by reservation of wavelengths and time slots.

Traffic engineering for MPLS

Abstract: An analytical model is developed in this paper for evaluating the performance of bandwidth allocation algorithms, with or without preemption, when used for Diffserv-aware MPLS traffic engineering. It is shown that, a major difference between various algorithms is their capabilities to provide greater bandwidth sharing versus robust service protection/isolation.

Size-based adaptive bandwidth allocation: optimizing the average QoS for elastic flows

Abstract: With a view on improving user perceived performance on networks supporting elastic flows, e.g., multimedia/data file transfers, we identify the key properties that an online dynamic bandwidth allocation policy should have. We then propose a family of bandwidth allocation criteria which depends on the residual work of on-going transfers. Analysis and simulations show that allocating bandwidth in this fashion can improve the user perceived average bit transmission delay (BTD), i.e., delay/flow size, by up to 70% at 80% traffic load over traditional approaches. A simple implementation based upon TCP Reno, exemplifies how one might approach practically realizing such gains. Further studies on simple network topologies show that as the penetration of the proposed transport mechanism increases, users will have the proper incentives to upgrade from TCP Reno, and that the overall performance is better for all users once the penetration exceeds 20%.

Allocation of bandwidth and storage

Abstract: We consider two allocation problems in this paper, namely, allocation of bandwidth and storage. In these problems, we face a number of independent requests, respectively, for reservation of bandwidth of a communication channel of fixed capacity and for storage of items into a space of fixed size. In both problems, a request is characterized by: (i) its required period of allocation; (ii) its required bandwidth (item width, respectively); and (iii) the profit of accepting the request. The problem is to decide which requests to accept so as to maximize the total profit. These problems in general are NP-hard. In this paper we provide polynomial-time algorithms for solving various special cases, and develop polynomial-time approximation algorithms for very general NP-hard cases with good performance guarantees.