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Topic: Adaptive switching


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  Fragment free cut-through - Wikipedia, the free encyclopedia
Because of this, fragment-free switching cannot pass packets to higher speed networks, for example, to forward packets from a 10 Mbit/s to a 100 Mbit/s Ethernet network.
Fragment-free switching offers a compromise between cut through (which offers the fastest possible forwarding at the expense of any error checking) and store-and-forward (which offers maximum error checking at the expense of latency), to provide an average latency of approximately 60µs and sufficient error checking to eliminate most common errors.
Fragment-free switching checks that there are no collisions within the first 64 bytes of the packet--the minimum valid message size required by the IEEE 802.3 specification.
en.wikipedia.org /wiki/Fragment_free_cut-through   (258 words)

  
 Switching
Adaptive switching Adaptive switching mode is a user-defined facility to maximize the efficiency of the switch.
Message switching In packet switching, where messages were routed in their entirety, one hop at a time.
Packet switching In telecommunications, packet switching is a communications paradigm in which packets (messages or frag...
www.brainyencyclopedia.com /topics/switching.html   (338 words)

  
 Adaptive
Adaptive coding The recently developed technique of data compression in situations where a linear treatment is inappropr...
Adaptive enzyme Adaptive enzyme is an enzyme that is present in the cell only under conditions in which it is clear of a...
Adaptive optics Adaptive optics is a active optics, which works on a longer timescale to correct the mirror geometry its...
www.brainyencyclopedia.com /topics/adaptive.html   (221 words)

  
 Adaptive Switching Control Applied to Multivariable Systems   (Site not responding. Last check: 2007-09-17)
In this thesis, a family of adaptive control problems is examined and solved using robust self-tuning switching controllers.
More specifically, for the adaptive control problem of a family of not necessarily strictly proper multi-input multi-output (MIMO) plants, a switching mechanism which requires less a priori system information than previously considered is proposed.
Real-time experimental results of one particular class of switching controllers when applied to a multivariable hydraulic apparatus are presented, and illustrate the feasibility of applying such adaptive controllers to industrial process control problems.
www.control.toronto.edu /theses/m_chang.html   (230 words)

  
 Time-discrete adaptive switching on-off controller
switching means which activates one or the other of said control means in dependence of the result of a measurement of the process output and a current setpoint, said actuator being controlled by the control means which is activated by the switching means.
Within the last decades adaptive controllers have been developed which are--contrary to controllers with fixed parameters--able to adapt to the momentary operating conditions of the process to be controlled, thus increasing the quality of control of processes that are insufficiently known or time-variant.
It activates the control device 30 by means of the switches 55 and 56, when the distance between setpoint w and measured value y in the signal sequence x is smaller or equal to a prefixed distance during the transient phase control of the process by means of the control device 40.
www.freepatentsonline.com /4639853.html   (7636 words)

  
 Discrete time control apparatus
switching means for selecting, one at a time, said discrete-time adaptive switching control means and said continuous manipulated-variable sampling control means based on a target preset value and the present controlled variable.
A discrete-time adaptive switching control (ASC) estimates and updates model parameters at each sampling interval, based on a manipulated variable to be applied to an actuator for effecting the binary switching mode and the controlled variable detected by the sampling/detecting apparatus in order to adapt a discrete-time model to the system.
Switches are used for selecting, one at a time, discrete-time adaptive switching control and continuous manipulated-variable sampling control based on a target preset value and the present controlled variable.
www.freepatentsonline.com /4791548.html   (3709 words)

  
 Adaptive switching speed control for pulse width modulation - US Patent 6476683   (Site not responding. Last check: 2007-09-17)
Different switching slew rates are used for different working modes, which include the normal mode where EMI reduction is given priority and an over-current mode, where reduction of switching losses is given priority.
In the over-current mode, the switching slew rates for the falling edge are large, providing a short switching transition to reduce switching losses and avoid damage to the switching component.
In the over-temperature mode, an intermediate switching slew rate between that of the normal mode and the over-current modes is used.
www.patentstorm.us /patents/6476683.html   (4928 words)

  
 Adaptive fault-tolerant switching network with random initial routing and random routing around faults - US Patent ...   (Site not responding. Last check: 2007-09-17)
Source switch 52 randomly chooses a switch in the fabric to be random switch 56, and writes the identifier or address of random switch 56 to an initial or random destination field in the packet's header.
When the congested switch is on the only route toward the packet destination, then the switch where the packet resides keeps the packet until the congestion condition is eliminated or sends the packet to a random switch in the network.
The random switch is chosen in a "random" manner in the sense that it is random with respect to the source and destination.
www.patentstorm.us /patents/6594261.html   (9979 words)

  
 Adaptive switching - Wikipedia, the free encyclopedia
Adaptive switching mode is a user-defined facility to maximize the efficiency of the switch.
Adaptive switching starts in the default switch forwarding mode you have selected (cut-through if you selected adaptive mode as the default switching mode).
Depending on the number of runts and CRC errors at that port, the mode changes to the "best" of the other two switching modes.
en.wikipedia.org /wiki/Adaptive_switching   (109 words)

  
 Switches - What Are Forwarding Modes and How Do They Work?
Cut-through switching sends the packet to the destination as soon as the first 14 bytes of the packet are read--an approximate latency of 25 microseconds for 10Mbps devices and 7 microseconds for 100Mbps devices.
Since the switch has forwarded most of the packet when the CRC is read, the switch cannot discard packets with CRC errors.
Fragment-free switching offers a compromise between cut-through (which offers the fastest possible forwarding at the expense of error checking) and store-and-forward (which offers maximum error checking at the expense of forwarding speed), to provide a latency of approximately 60 microseconds and sufficient error checking to eliminate the most common errors.
www.intel.com /support/express/switches/sb/cs-014410.htm   (877 words)

  
 Intel® Express 10 Switch - Switch Forwarding Modes
If a switch buffers an entire frame before forwarding the frame on another port (store-and-forward mode), the switching latency will depend on the frame size, which can be a severe performance drawback, especially if multimedia applications are used on the network.
As soon as the switch has read the destination and source addresses and the type field, the frame is forwarded on the destination port.
The main drawback with cut-through switching is that error frames (such as collision fragments) are also forwarded, as long as they exceed 14 bytes.
www.intel.com /support/express/switches/10/sb/cs-014377.htm   (489 words)

  
 Dictionary of Meaning www.mauspfeil.net
Serialization time for a 1500 bytes packet is around 120 microseconds, substantially lower than people care for, and with Gigabit Ethernet it decreases to 120 ns, which people probably cant't even measure with standard computers any more.
For instance, the last Cisco switch to offer features in that regard has been the 2820, which was 10Mbit technology and has been out of sale for years now.
There you find a list of all editors and the possibility to edit the original text of the article Adaptive switching.
www.mauspfeil.net /Adaptive_switching.html   (360 words)

  
 ECS EPrints Service - Optimum Mode-Switching Assisted Adaptive Modulation
Adaptive modulation techniques combat fading by employing a suitable modulation mode depending on the instantaneous channel conditions for improving the Bit Error Rate (BER) performance or the average through-put.
Based on a generic model of constant-power adaptive modulation, exact closed form expressions of the average BER and the average throughput are derived, when employing square Quadrature Amplitude Modulation (QAM) or Phase Shift Keying (PSK) as the constituent modulation modes, operating over a Nakagami fading channel.
The optimum modulation-mode switching levels, achieving the highest possible throughput under the constraint of the average BER, are obtained using the Lagrangian optimisation method.
eprints.ecs.soton.ac.uk /6180   (172 words)

  
 IEEE Canada Digital Library
Several switching techniques are described, including some recent hybrid techniques, and highlighting the relationship between switching technique and network technology.
Adaptive routing algorithms have the potential to increase link utilization and throughput by avoiding congested regions in the network.
Several methodologies for the design of addaptive routing algorithms are described, as well as their application to multicomputer networks and networks of workstations with irregular topologies.
www.ewh.ieee.org /reg/7/diglib/library/9706duato/duato.htm   (446 words)

  
 Method and arrangement for adaptive switching off of the exhaust brake in connection with upshift
A method according to claim 5, wherein the predetermined time is decreased by an adaptive offset value (EBA.sub.off) and the adaptive offset value is stored in a non-volatile memory.
Switching off too early on uphill runs may result in the engine speed never catching up with the synchronous speed, which will decrease continuously because of the vehicle's retardation.
The invention described results in adaptive adjustment of the exhaust brake switch-off point for subsequent upshifts so that Maxdip, on the basis of the engine speed bracketing pattern from the previous upshift, is kept within predetermined optimum limits below the synchronous engine speed n.sub.1.
www.freepatentsonline.com /5568387.html   (4474 words)

  
 Multihypothesis Motion-Compensated Prediction with Forward-Adaptive Hypothesis Switching   (Site not responding. Last check: 2007-09-17)
We study the influence of the hypothesis set size M on both the accuracy of motion compensation of forward-adaptive hypothesis switching and the efficiency of multihypothesis motion-compensated prediction.
Selecting one hypothesis from a set of motion-compensated signals of size M, that is, switching among M hypotheses, will reduce the displacement error variance by factor M when we assume statistically independent displacement errors.
Integrating forward-adaptive hypothesis switching into multihypothesis motion-compensated prediction, that is, allowing a combination of switched hypotheses, increases the gain of multihypothesis motion-compensated prediction over the single hypothesis case for growing hypothesis set size M.
www-nt.e-technik.uni-erlangen.de /~flierl/Publications/flierl:01-PCS.html   (205 words)

  
 Impact of antenna geometry in MIMO communication in indoor clustered channels   (Site not responding. Last check: 2007-09-17)
We consider a low-complexity adaptive MIMO transmission approach for spatially correlated channels.
The proposed scheme adaptively switches between statistical beamforming, spatial multiplexing and double space-time transmit diversity, depending on the changing channel conditions.
We then present a practical switching procedure based on a simple metric derived from the estimated spatial correlation matrices and average signal to noise ratio.
www.ece.utexas.edu /~rheath/papers/2005/pimrc   (129 words)

  
 Adaptive Sampling with Switching Costs or Constraints   (Site not responding. Last check: 2007-09-17)
It is observed that the expected number of switches grows approximately as the square root of the sample size, for sample sizes up to a few hundred, when on optimal sequential allocation is performed with no regard for switching.
It is also observed that one can dramatically reduce the number of switches without substantially affecting the expected value of the objective function, as long as the switches are made optimally.
The algorithms developed herein are used in New Adaptive Designs that Incorporate Switching Concerns in the design and analysis of optimal and hyperopic procedures.
www.eecs.umich.edu /~qstout/abs/IF96.html   (246 words)

  
 ALATE Dynamic Programming Overview
There are two main application areas: adaptive (sequential) designs for random responses, and determining properties of graphs.
Much of the work on adaptive designs has been motivated by problems in allocating patients to treatments in a clinical trial or in industrial applications of estimation or fault tolerance, though other areas are also being worked on.
He is also working on programs for several other aspects of adaptive designs, and more generally on the problem of producing efficient highly parallel programs for dynamic programming.
www.eecs.umich.edu /~qstout/dynamprog.html   (2107 words)

  
 [No title]
By a logic-based switching controller is meant a controller whose subsystems include not only familiar dynamical components such as integrators, summers, gains, etc., but a nontrivial logical component as well.
Toward this end detailed analyses, simulation studies and laboratory experiments of such systems have been initiated in a variety of disciplines including adaptive control, gain scheduling, control of nonholonomic systems, motion control, and the control of saturation constrained systems.
The primary purpose of the workshop is to bring together a small number of specialists working within the area for the purpose of crystallizing concepts, problem formulations, and approaches.
www-control.eng.cam.ac.uk /extras/conferences/CLBS95   (439 words)

  
 Adaptive Designs that Incorporate Switching Concerns   (Site not responding. Last check: 2007-09-17)
To illustrate the effects of the switching restrictions, they are applied to a 2-arm bandit problem.
It is observed that when there are no restrictions the expected number of switches in the optimal allocation grows approximately as the square root of the sample size, for sample sizes up to a few hundred.
It is also observed that one can dramatically reduce the number of switches without substantially affecting the expected value of the objective function.
www.eecs.umich.edu /~qstout/abs/StPete05.html   (313 words)

  
 Non-mechanically-axial-scanning confocal microscope using adaptive mirror switching
The system controls the defocus of an objective into three to.ve optimized states by using a membrane-adaptive mirror, and determines the axial height of an object according to the confocal output value with each defocus.
A genetic algorithm is employed to optimize the adaptive mirror shape, with the information entropy of the spectrum of the lateral confocal spot pro.le used as a cost function in the genetic algorithm.
Ruprecht, and H. Tiziani, "Non-mechanically-axial-scanning confocal microscope using adaptive mirror switching," Opt.
www.opticsexpress.org /abstract.cfm?URI=OPEX-11-1-54   (323 words)

  
 Citations: Adaptive switching circuits - Widrow, Hoff (ResearchIndex)   (Site not responding. Last check: 2007-09-17)
Citations: Adaptive switching circuits - Widrow, Hoff (ResearchIndex)
Widrow and M.E. Hoff, "Adaptive switching circuits," in IRE WESCON, New-York, 1960, pp.
Widrow, B.; Ho Jr., M.E.: Adaptive switching circuits.
citeseer.ist.psu.edu /context/9072/0   (2757 words)

  
 Compaq Access - Support Software for Compaq Network Products   (Site not responding. Last check: 2007-09-17)
ADAPTive Switching is our Advanced Dynamic Access Partitioning Technology.
This allows incoming calls to dynamically switch to the intended virtual private network (VPN) by assigning WAN ports to multiple output ports or applications on a call-by-call basis.
You must use an ADMM controller to configure the 20 port Ethernet hub, the 4 port Etherflex module and the 2 port MNC II to use multiple segments.
h18000.www1.hp.com /support/faqs/Microcom6000FAQs.html   (1334 words)

  
 Optimum Mode-Switching Assisted Adaptive Modulation (ResearchIndex)   (Site not responding. Last check: 2007-09-17)
Abstract: Adaptive modulation techniques combat fading by employing a suitable modulation mode depending on the instantaneous channel conditions for improving the Bit Error Rate (BER) performance or the average throughput.
Based on a generic model of constant-power adaptive modulation, exact closed form expressions of the average BER and the average throughput are derived, when employing square Quadrature Amplitude Modulation (QAM) or Phase Shift Keying (PSK) as the constituent modulation modes,...
12 Upper bound performance of adaptive modulation in a slow Ray..
citeseer.ist.psu.edu /503924.html   (392 words)

  
 Cray moves to port-able switching - Computerworld   (Site not responding. Last check: 2007-09-17)
Cray Communications Corp. is upgrading its Ethernet switches to include a technology that automatically selects the best data transmission method on a per-port basis.
Some current switches can move the entire network from one mode to another for optimal performance, but the Cray technology differs in that modes can be changed per port.
Users said they were enthusiastic about the MatchBox switches because they are upgrading their backbone networks to higher speeds and want to switch at the highest speeds, except when errors accrue in data transmissions.
www.computerworld.com /printthis/1996/0,4814,6527,00.html   (451 words)

  
 Published Works   (Site not responding. Last check: 2007-09-17)
Adaptive and Learning Systems, Edited by K.S. Narendra, Plennum Press, New York, June, 1985 (chapter on flow control in data networks).
F. Vazquez-Abad, L.G. Mason, "Adaptive Decentralized Control of DEDS under Non-uniqueness of the Optimal Control", Journal of Discrete Event Dynamic Systems: Theory and Applications, 6,323-359 (1996).
A. Pelletier, M. Cotton, L.G. Mason, "Combined Adaptive Routing and Flow Control in Fast Packet Switching Networks", Proceedings of COMCON 4, Rhodes, Greece, June 1993.
www.tsp.ece.mcgill.ca /Mason/Publications/Papers.htm   (2718 words)

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