Search results for "Distributed coordination function"

showing 10 items of 14 documents

Refinements on IEEE 802.11 Distributed Coordination Function Modeling Approaches

2010

With the popularity of the IEEE 802.11 standards, many analytical saturation throughput studies for the distributed coordination function (DCF) have been reported. In this paper, we outline a number of issues and criticalities raised by previously proposed models. In particular, a careful look at backoff counter decrement rules allows us to conclude that, under saturation conditions, the slot immediately following a successful transmission can be accessed only by the station (STA) that has successfully transmitted in the previous channel access. Moreover, due to the specific acknowledgment (ACK) timeout setting adopted in the standard, the slot immediately following a collision cannot be ac…

Computer Networks and Communicationscomputer.internet_protocolComputer scienceAerospace EngineeringThroughputDistributed coordination functionIEEE 802.11Wireless lanWireless Application ProtocolElectrical and Electronic Engineeringbusiness.industrySettore ING-INF/03 - Telecomunicazioni802.11 Performance analysisWiFiPerformance analysisComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSCode ratemedium access protocolsAutomotive EngineeringbusinessTimeoutcomputerWireless sensor network802.11Computer networkCommunication channel
researchProduct

Out-of-Band Signaling Scheme for High Speed Wireless LANs

2007

In recent years, the physical layer data rate provided by 802.11 Wireless LANs has dramatically increased thanks to significant advances in the modulation and coding techniques employed. However, previous studies show that the 802.11 MAC operation, namely the distributed coordination function (DCF), represents a limiting factor: the throughput efficiency drops as the channel bit rate increases, and a throughput upper limit does indeed exist when the channel bit rate goes to infinite high. These findings indicate that the performance of the DCF protocol will not be efficiently improved by merely increasing the channel bit rate. This paper shows that the DCF performance may significantly bene…

Computer scienceComputer network performanceWireless LANThroughputDistributed coordination functionBackward compatibilityIEEE 802.11Packet switchingWireless lanWireless LAN Throughput Bit rate Physical layer Modulation coding Access protocols Content management Signal design Media Access Protocol Performance analysisElectrical and Electronic EngineeringIEEE 802.11Settore ING-INF/03 - Telecomunicazionibusiness.industryApplied MathematicsComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSPhysical layerCode rateComputer Science ApplicationsComputer network performance; IEEE 802.11; Wireless LANBurst switchingModulationOut-of-band managementbusinessCommunication channelComputer networkIEEE Transactions on Wireless Communications
researchProduct

Remarks on IEEE 802.11 DCF performance analysis

2005

This letter presents a new approach to evaluate the throughput/delay performance of the 802.11 distributed coordination function (DCF). Our approach relies on elementary conditional probability arguments rather than bidimensional Markov chains (as proposed in previous models) and can be easily extended to account for backoff operation more general than DCF's one.

Computer scienceMarkov processThroughputDistributed coordination functionCarrier-sense multiple accesssymbols.namesakeIEEE 802.11Wireless lanComputer Science::Networking and Internet ArchitectureElectrical and Electronic EngineeringThroughput (business)IEEE 802.11Markov chainSettore ING-INF/03 - Telecomunicazionibusiness.industryComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSComputer Science ApplicationsComputer Science::PerformanceModeling and SimulationMultiple access controlPerformance evaluationsymbolsIEEE 802.11; Multiple access control; Performance evaluationbusinessAlgorithmComputer networkIEEE Communications Letters
researchProduct

The role of the Access Point in Wi-Fi networks with selfish nodes

2009

In Wi-Fi networks, mobile nodes compete for accessing the shared channel by means of a random access protocol called Distributed Coordination Function (DCF), which is long term fair. But recent drivers allow users to configure protocol parameters differently from their standard values in order to break the protocol fairness and obtain a larger share of the available bandwidth at the expense of other users. This motivates a game theoretical analysis of DCF. Previous studies have already modeled access to a shared wireless channel in terms of non-cooperative games among the nodes, but they have mainly considered ad hoc mode operation. In this paper we consider the role of the Access Point (AP…

Computer scienceWireless ad hoc networkBidirectional trafficDistributed computingmedia_common.quotation_subjectMechanism designThroughputDistributed coordination functionNash equilibriumWi-fi networks[INFO.INFO-NI]Computer Science [cs]/Networking and Internet Architecture [cs.NI]IEEE 802.11Settore ING-INF/04 - Automaticaselfish nodesSelfishnessmedia_commonIEEE 802.11business.industrySettore ING-INF/03 - TelecomunicazioniNode (networking)ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSWLAN; selfish nodesWLANbusinessRandom accessComputer network
researchProduct

Resource sharing optimality in WiFi infrastructure networks

2009

In WiFi networks, mobile nodes compete for accessing a shared channel by means of a random access protocol called Distributed Coordination Function (DCF). Although this protocol is in principle fair, since all the stations have the same probability to transmit on the channel, it has been shown that unfair behaviors may emerge in actual networking scenarios. Assuming that a contending node can dynamically change its strategy, by tuning its contention parameters to non-standard values on the basis of channel observations, we prove that, for infrastructure networks with bidirectional traffic and homogeneous application requirements, selfish access strategies are able to reach equilibrium condi…

Computer sciencebusiness.industryBidirectional trafficSettore ING-INF/03 - TelecomunicazioniDistributed computingNode (networking)ThroughputDistributed coordination functionShared resourceSettore ING-INF/04 - AutomaticaWireless lanTelecommunications linkMobile telephonybusinessGame theory Mechanism Design WiFi Infrastructure NetworksRandom accessCommunication channelComputer network
researchProduct

Impact of LTE’s Periodic Interference on Heterogeneous Wi-Fi Transmissions

2018

The problem of Wi-Fi and LTE coexistence has been significantly debated in the last years, with the emergence of LTE extensions enabling the utilization of unlicensed spectrum for carrier aggregation. Rather than focusing on the problem of resource sharing between the two technologies, in this paper, we study the effects of LTE's structured transmissions on the Wi-Fi random access protocol. We show how the scheduling of periodic LTE transmissions modifies the behavior of 802.11's distributed coordination function (DCF), leading to a degradation of Wi-Fi performance, both in terms of channel utilization efficiency and in terms of channel access fairness. We also discuss the applicability and…

FOS: Computer and information sciencesComputer scienceThroughput02 engineering and technologyDistributed coordination functionSpectrum managementAnalytical modelScheduling (computing)Computer Science - Networking and Internet ArchitectureC.2.0C.2.50202 electrical engineering electronic engineering information engineeringLong Term EvolutionWireless fidelityElectrical and Electronic EngineeringProbabilitySensorNetworking and Internet Architecture (cs.NI)business.industrySettore ING-INF/03 - TelecomunicazioniComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS020206 networking & telecommunicationsComputer Science Applications1707 Computer Vision and Pattern RecognitionThroughput91A06 91A10 91A80Computer Science ApplicationsShared resourceModeling and SimulationbusinessC.2.0; C.2.5InterferenceRandom accessComputer networkCommunication channel
researchProduct

MAC Design for WiFi Infrastructure Networks: A Game-Theoretic Approach

2011

In WiFi networks, mobile nodes compete for accessing a shared channel by means of a random access protocol called Distributed Coordination Function (DCF). Although this protocol is in principle fair, since all the stations have the same probability to transmit on the channel, it has been shown that unfair behaviors may emerge in actual networking scenarios because of non-standard configurations of the nodes. Due to the proliferation of open source drivers and programmable cards, enabling an easy customization of the channel access policies, we propose a game-theoretic analysis of random access schemes. Assuming that each node is rational and implements a best response strategy, we show that…

FOS: Computer and information sciencesgame theorycheating nodeaccess protocolsmobile nodesComputer sciencegame-theoretic approachMAC designDistributed coordination functionUpload[INFO.INFO-NI]Computer Science [cs]/Networking and Internet Architecture [cs.NI]MAC protocolschannel access policyComputer Science - Computer Science and Game TheoryFOS: MathematicsElectrical and Electronic EngineeringMathematics - Optimization and Controlwireless LANdistributed coordination functionMechanism designcheating nodesWiFi infrastructure networksbusiness.industryApplied MathematicsNode (networking)WiFiComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSWiFi; cheating nodes; game theory; MAC protocolsComputer Science ApplicationsShared resourceprogrammable cardsOptimization and Control (math.OC)game-theoretic analysisBest responserandom access schemebusinessrandom access protocolRandom accessCommunication channelComputer networkComputer Science and Game Theory (cs.GT)
researchProduct

Cooperative RTS/CTS MAC with relay selection in distributed wireless networks

2009

This paper proposes a cooperative multiple access protocol based on the Distributed Coordination Function (DCF) Request-To-Send/Clear-To-Send (RTS/CTS) scheme for distributed wireless networks. It answers three key questions concerning cooperation from the network perspective, namely when to cooperate, whom to cooperate with and how to protect cooperative transmissions. According to our protocol, the cooperation is initiated only if the direct transmission fails. An optimal relay node is selected in a distributed manner according to instantaneous relay channel conditions without prior information or extra signaling among relay candidates in the network. An additional three-way handshake is …

Hidden node problemComputer sciencebusiness.industryWireless networkNode (networking)ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSDistributed coordination functionlaw.inventionCooperative diversityRelaylawMultiple Access with Collision Avoidance for WirelessbusinessRelay channelComputer network2009 International Conference on Ultra Modern Telecommunications & Workshops
researchProduct

Revisit of RTS/CTS Exchange in High-Speed IEEE 802.11 Networks

2005

IEEE 802.11 medium access control (MAC), called distributed coordination function (DCF), provides two different access modes, namely, 2-way (basic access) and 4-way (RTS/CTS) handshaking. The 4-way handshaking has been introduced in order to combat the hidden terminal phenomenon. It has been also proved that such a mechanism can be beneficial even in the absence of hidden terminals, because of the collision time reduction. We analyze the effectiveness of the RTS/CTS access mode, in current 802.11b and 802.11a networks. Since the rates employed for control frame transmissions can be much lower than the rate employed for data frames, the assumption on the basis of the 4-way handshaking introd…

Hidden node problembusiness.industryComputer scienceReal-time computingFrame (networking)Wireless local area networks (WLAN)Distributed coordination functionThroughputbackoff algorithmHandshakingMedia access controlMultiple Access with Collision Avoidance for WirelessIEEE 802.11e-2005businessCarrier sense multiple access with collision avoidanceComputer networkSixth IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks
researchProduct

Analysis of the IEEE 802.11e EDCA Under Statistical Traffic

2006

Many models have been proposed to analyze the performance of the IEEE 802.11 distributed coordination function (DCF) and the IEEE 802.11e enhanced distributed coordination function (EDCA) under saturation condition. To analyze DCF under statistical traffic, Foh and Zukerman introduce a model that uses Markovian Framework to compute the throughput and delay performance. In this paper, we analyze the protocol service time of EDCA mechanism and introduce a model to analyze EDCA under statistical traffic using Markovian Framework. Using this model, we analyze the throughput and delay performance of EDCA mechanism under statistical traffic.

IEEE 802Computer sciencebusiness.industryQuality of serviceComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSMarkov processWireless local area networks (WLAN)ThroughputDistributed coordination functionThroughputComputer Science::OtherComputer Science::Performancebackoff algorithmsymbols.namesakeWireless lanComputer Science::Networking and Internet ArchitecturesymbolsbusinessThroughput (business)Protocol (object-oriented programming)Computer network
researchProduct